Vue.js - How to implement Computed properties on objects of array?
up vote
1
down vote
favorite
I have an array of objects inside my Vue instance, and for each item I'd like to write a Computed property.
Each object has only two properties: firstName and lastName. I would like to write a Computed property for each named 'fullName', which is just a concatenation of firstName and lastName.
I'm familiar with implementing Computed properties of data object properties of a Vue instances, but when it comes to doing so with elements of an array, I get confused.
Currently, my code is this:
var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
}
}
methods: {
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in names'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ fullName(name) }}</span>
<del v-else>{{ fullName(name) }}</del>
</li>
</ol>
</div>And here is the respective jsFiddle
javascript vue.js vuejs2 computed-properties
edited Nov 20 at 17:00
Boussadjra Brahim
4,7053629
asked Nov 20 at 16:04
Delfino
4191623
add a comment |
up vote
1
down vote
favorite
I have an array of objects inside my Vue instance, and for each item I'd like to write a Computed property.
Each object has only two properties: firstName and lastName. I would like to write a Computed property for each named 'fullName', which is just a concatenation of firstName and lastName.
I'm familiar with implementing Computed properties of data object properties of a Vue instances, but when it comes to doing so with elements of an array, I get confused.
Currently, my code is this:
var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
}
}
methods: {
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in names'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ fullName(name) }}</span>
<del v-else>{{ fullName(name) }}</del>
</li>
</ol>
</div>And here is the respective jsFiddle
javascript vue.js vuejs2 computed-properties
edited Nov 20 at 17:00
Boussadjra Brahim
4,7053629
asked Nov 20 at 16:04
Delfino
4191623
1
Try to reduce the number of function calls in your template. The function results are not cached, meaning that pretty much every change in data causes a full re-render. Using a computed, by creating an array of pre-computed objects can greatly improve your apps performance. See @Boussadjra's updated (2nd) example
– Daniel
Nov 20 at 16:31
add a comment |
up vote
1
down vote
favorite
up vote
1
down vote
favorite
I have an array of objects inside my Vue instance, and for each item I'd like to write a Computed property.
Each object has only two properties: firstName and lastName. I would like to write a Computed property for each named 'fullName', which is just a concatenation of firstName and lastName.
I'm familiar with implementing Computed properties of data object properties of a Vue instances, but when it comes to doing so with elements of an array, I get confused.
Currently, my code is this:
var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
}
}
methods: {
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in names'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ fullName(name) }}</span>
<del v-else>{{ fullName(name) }}</del>
</li>
</ol>
</div>And here is the respective jsFiddle
javascript vue.js vuejs2 computed-properties
edited Nov 20 at 17:00
Boussadjra Brahim
4,7053629
asked Nov 20 at 16:04
Delfino
4191623
I have an array of objects inside my Vue instance, and for each item I'd like to write a Computed property.
Each object has only two properties: firstName and lastName. I would like to write a Computed property for each named 'fullName', which is just a concatenation of firstName and lastName.
I'm familiar with implementing Computed properties of data object properties of a Vue instances, but when it comes to doing so with elements of an array, I get confused.
Currently, my code is this:
var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
}
}
methods: {
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in names'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ fullName(name) }}</span>
<del v-else>{{ fullName(name) }}</del>
</li>
</ol>
</div>And here is the respective jsFiddle
var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
}
}
methods: {
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in names'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ fullName(name) }}</span>
<del v-else>{{ fullName(name) }}</del>
</li>
</ol>
</div>var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
}
}
methods: {
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in names'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ fullName(name) }}</span>
<del v-else>{{ fullName(name) }}</del>
</li>
</ol>
</div>javascript vue.js vuejs2 computed-properties
javascript vue.js vuejs2 computed-properties
edited Nov 20 at 17:00
Boussadjra Brahim
4,7053629
asked Nov 20 at 16:04
Delfino
4191623
edited Nov 20 at 17:00
Boussadjra Brahim
4,7053629
asked Nov 20 at 16:04
Delfino
4191623
edited Nov 20 at 17:00
Boussadjra Brahim
4,7053629
edited Nov 20 at 17:00
Boussadjra Brahim
4,7053629
edited Nov 20 at 17:00
Boussadjra Brahim
4,7053629
4,7053629
asked Nov 20 at 16:04
Delfino
4191623
asked Nov 20 at 16:04
Delfino
4191623
asked Nov 20 at 16:04
Delfino
4191623
4191623
1
Try to reduce the number of function calls in your template. The function results are not cached, meaning that pretty much every change in data causes a full re-render. Using a computed, by creating an array of pre-computed objects can greatly improve your apps performance. See @Boussadjra's updated (2nd) example
– Daniel
Nov 20 at 16:31
add a comment |
1
Try to reduce the number of function calls in your template. The function results are not cached, meaning that pretty much every change in data causes a full re-render. Using a computed, by creating an array of pre-computed objects can greatly improve your apps performance. See @Boussadjra's updated (2nd) example
– Daniel
Nov 20 at 16:31
1
1
Try to reduce the number of function calls in your template. The function results are not cached, meaning that pretty much every change in data causes a full re-render. Using a computed, by creating an array of pre-computed objects can greatly improve your apps performance. See @Boussadjra's updated (2nd) example
– Daniel
Nov 20 at 16:31
Try to reduce the number of function calls in your template. The function results are not cached, meaning that pretty much every change in data causes a full re-render. Using a computed, by creating an array of pre-computed objects can greatly improve your apps performance. See @Boussadjra's updated (2nd) example
– Daniel
Nov 20 at 16:31
add a comment |
2 Answers
2
active
oldest
votes
up vote
2
down vote
accepted
You could use fullname as method instead of computed property in your case :
var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
},
methods: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
},
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in names'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ fullName(name) }}</span>
<del v-else>{{ fullName(name) }}</del>
</li>
</ol>
</div>Another solution is to loop through names array inside a computed property by concatenating firstname and lastname, after that return this array and loop through it in your template
var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
fullNames() {
return this.names.map(name => {
let fl = {};
fl.fname = name.firstName + ", " + name.lastName;
fl.done = name.done;
return fl;
})
}
},
methods: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
},
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in fullNames'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ name.fname }}</span>
<del v-else>{{ name.fname }}</del>
</li>
</ol>
</div>answered Nov 20 at 16:13
Boussadjra Brahim
4,7053629
Seems that if having to loop through eachnameinnamesin a Computed property, it would be easier to set up a method.
– Delfino
Nov 20 at 16:23
1
i added a second solution using computed property
– Boussadjra Brahim
Nov 20 at 16:25
add a comment |
up vote
1
down vote
You can't use the 'computed' with a parameter.
Most probably you want to use a method:
example
<span>{{ fullName('Hi') }}</span>
methods: {
fullName(param) {
return `${this.param} ${this.firstName} ${this.lastName}`
}
}
answered Nov 20 at 16:17
Seb
8029
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
draft saved
draft discarded
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53396969%2fvue-js-how-to-implement-computed-properties-on-objects-of-array%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
2
down vote
accepted
You could use fullname as method instead of computed property in your case :
var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
},
methods: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
},
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in names'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ fullName(name) }}</span>
<del v-else>{{ fullName(name) }}</del>
</li>
</ol>
</div>Another solution is to loop through names array inside a computed property by concatenating firstname and lastname, after that return this array and loop through it in your template
var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
fullNames() {
return this.names.map(name => {
let fl = {};
fl.fname = name.firstName + ", " + name.lastName;
fl.done = name.done;
return fl;
})
}
},
methods: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
},
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in fullNames'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ name.fname }}</span>
<del v-else>{{ name.fname }}</del>
</li>
</ol>
</div>answered Nov 20 at 16:13
Boussadjra Brahim
4,7053629
Seems that if having to loop through eachnameinnamesin a Computed property, it would be easier to set up a method.
– Delfino
Nov 20 at 16:23
1
i added a second solution using computed property
– Boussadjra Brahim
Nov 20 at 16:25
add a comment |
up vote
2
down vote
accepted
You could use fullname as method instead of computed property in your case :
var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
},
methods: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
},
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in names'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ fullName(name) }}</span>
<del v-else>{{ fullName(name) }}</del>
</li>
</ol>
</div>Another solution is to loop through names array inside a computed property by concatenating firstname and lastname, after that return this array and loop through it in your template
var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
fullNames() {
return this.names.map(name => {
let fl = {};
fl.fname = name.firstName + ", " + name.lastName;
fl.done = name.done;
return fl;
})
}
},
methods: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
},
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in fullNames'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ name.fname }}</span>
<del v-else>{{ name.fname }}</del>
</li>
</ol>
</div>answered Nov 20 at 16:13
Boussadjra Brahim
4,7053629
Seems that if having to loop through eachnameinnamesin a Computed property, it would be easier to set up a method.
– Delfino
Nov 20 at 16:23
1
i added a second solution using computed property
– Boussadjra Brahim
Nov 20 at 16:25
add a comment |
up vote
2
down vote
accepted
up vote
2
down vote
accepted
You could use fullname as method instead of computed property in your case :
var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
},
methods: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
},
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in names'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ fullName(name) }}</span>
<del v-else>{{ fullName(name) }}</del>
</li>
</ol>
</div>Another solution is to loop through names array inside a computed property by concatenating firstname and lastname, after that return this array and loop through it in your template
var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
fullNames() {
return this.names.map(name => {
let fl = {};
fl.fname = name.firstName + ", " + name.lastName;
fl.done = name.done;
return fl;
})
}
},
methods: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
},
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in fullNames'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ name.fname }}</span>
<del v-else>{{ name.fname }}</del>
</li>
</ol>
</div>answered Nov 20 at 16:13
Boussadjra Brahim
4,7053629
You could use fullname as method instead of computed property in your case :
var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
},
methods: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
},
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in names'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ fullName(name) }}</span>
<del v-else>{{ fullName(name) }}</del>
</li>
</ol>
</div>Another solution is to loop through names array inside a computed property by concatenating firstname and lastname, after that return this array and loop through it in your template
var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
fullNames() {
return this.names.map(name => {
let fl = {};
fl.fname = name.firstName + ", " + name.lastName;
fl.done = name.done;
return fl;
})
}
},
methods: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
},
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in fullNames'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ name.fname }}</span>
<del v-else>{{ name.fname }}</del>
</li>
</ol>
</div>var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
},
methods: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
},
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in names'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ fullName(name) }}</span>
<del v-else>{{ fullName(name) }}</del>
</li>
</ol>
</div>var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
},
methods: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
},
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in names'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ fullName(name) }}</span>
<del v-else>{{ fullName(name) }}</del>
</li>
</ol>
</div>var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
fullNames() {
return this.names.map(name => {
let fl = {};
fl.fname = name.firstName + ", " + name.lastName;
fl.done = name.done;
return fl;
})
}
},
methods: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
},
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in fullNames'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ name.fname }}</span>
<del v-else>{{ name.fname }}</del>
</li>
</ol>
</div>var app = new Vue({
el: '#app',
data: {
names: [{
firstName: 'Mike',
lastName: 'McDonald',
done: false
},
{
firstName: 'Alex',
lastName: 'Nemeth',
done: false
},
{
firstName: 'Nate',
lastName: 'Kostansek',
done: true
},
{
firstName: 'Ivan',
lastName: 'Wyrsta',
done: true
}
]
},
computed: {
fullNames() {
return this.names.map(name => {
let fl = {};
fl.fname = name.firstName + ", " + name.lastName;
fl.done = name.done;
return fl;
})
}
},
methods: {
fullName: function(name) {
return name.lastName + ', ' + name.firstName;
},
toggle: function(name) {
name.done = !name.done;
}
}
});<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<div id='app'>
<ol>
<li v-for='name in fullNames'>
<input type='checkbox' v-bind:checked='name.done' v-on:change='toggle(name)' />
<span v-if='!name.done'>{{ name.fname }}</span>
<del v-else>{{ name.fname }}</del>
</li>
</ol>
</div>answered Nov 20 at 16:13
Boussadjra Brahim
4,7053629
edited Nov 20 at 16:24
answered Nov 20 at 16:13
Boussadjra Brahim
4,7053629
answered Nov 20 at 16:13
Boussadjra Brahim
4,7053629
answered Nov 20 at 16:13
Boussadjra Brahim
4,7053629
4,7053629
Seems that if having to loop through eachnameinnamesin a Computed property, it would be easier to set up a method.
– Delfino
Nov 20 at 16:23
1
i added a second solution using computed property
– Boussadjra Brahim
Nov 20 at 16:25
add a comment |
Seems that if having to loop through eachnameinnamesin a Computed property, it would be easier to set up a method.
– Delfino
Nov 20 at 16:23
1
i added a second solution using computed property
– Boussadjra Brahim
Nov 20 at 16:25
Seems that if having to loop through each
name in names in a Computed property, it would be easier to set up a method.– Delfino
Nov 20 at 16:23
Seems that if having to loop through each
name in names in a Computed property, it would be easier to set up a method.– Delfino
Nov 20 at 16:23
1
1
i added a second solution using computed property
– Boussadjra Brahim
Nov 20 at 16:25
i added a second solution using computed property
– Boussadjra Brahim
Nov 20 at 16:25
add a comment |
up vote
1
down vote
You can't use the 'computed' with a parameter.
Most probably you want to use a method:
example
<span>{{ fullName('Hi') }}</span>
methods: {
fullName(param) {
return `${this.param} ${this.firstName} ${this.lastName}`
}
}
answered Nov 20 at 16:17
Seb
8029
add a comment |
up vote
1
down vote
You can't use the 'computed' with a parameter.
Most probably you want to use a method:
example
<span>{{ fullName('Hi') }}</span>
methods: {
fullName(param) {
return `${this.param} ${this.firstName} ${this.lastName}`
}
}
answered Nov 20 at 16:17
Seb
8029
add a comment |
up vote
1
down vote
up vote
1
down vote
You can't use the 'computed' with a parameter.
Most probably you want to use a method:
example
<span>{{ fullName('Hi') }}</span>
methods: {
fullName(param) {
return `${this.param} ${this.firstName} ${this.lastName}`
}
}
answered Nov 20 at 16:17
Seb
8029
You can't use the 'computed' with a parameter.
Most probably you want to use a method:
example
<span>{{ fullName('Hi') }}</span>
methods: {
fullName(param) {
return `${this.param} ${this.firstName} ${this.lastName}`
}
}
answered Nov 20 at 16:17
Seb
8029
answered Nov 20 at 16:17
Seb
8029
answered Nov 20 at 16:17
Seb
8029
answered Nov 20 at 16:17
Seb
8029
8029
add a comment |
add a comment |
draft saved
draft discarded
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
draft saved
draft discarded
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53396969%2fvue-js-how-to-implement-computed-properties-on-objects-of-array%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
1
Try to reduce the number of function calls in your template. The function results are not cached, meaning that pretty much every change in data causes a full re-render. Using a computed, by creating an array of pre-computed objects can greatly improve your apps performance. See @Boussadjra's updated (2nd) example
– Daniel
Nov 20 at 16:31