How to use map in vue

Map is used in Vue.js to store key-value pairs, where the keys can be of any data type. Usage methods include: creating Map, adding and accessing data, deleting data, and traversing data. Map is responsive and automatically updates the view when it changes.

Usage of Map in Vue.js

Map is a native JavaScript data structure that stores keys value pair. It is better suited for storing data than objects because keys can be any type of data, whereas keys in objects must be strings.

Using Map in Vue.js

In Vue.js, you can create a Map through the Vue.Map constructor:

<code class="javascript">const map = new Vue.Map();</code>

Also You can use ES6 Map syntax:

<code class="javascript">const map = new Map();</code>

Add and access data

Add key-value pairs to Map:

<code class="javascript">map.set('key', 'value');</code>

Get the value corresponding to the key:

<code class="javascript">map.get('key');</code>

Delete data

Delete key-value pairs from Map:

<code class="javascript">map.delete('key');</code>

Traverse data

Use forEach Traverse all key-value pairs in the Map:

<code class="javascript">map.forEach((value, key) => {
  console.log(`Key: ${key}, Value: ${value}`);
});</code>

Use entries to get the iterator of all key-value pairs:

<code class="javascript">const entries = map.entries();
for (let entry of entries) {
  console.log(`Key: ${entry[0]}, Value: ${entry[1]}`);
}</code>

Using Vue Reactivity

Map is reactive in Vue.js, which means that when the Map changes, the view automatically updates.

<code class="javascript">const map = Vue.observable(new Map());

map.set('key', 'value'); //视图自动更新</code>

Example

Create a Map with key-value pairs:

<code class="javascript">const map = new Vue.Map();
map.set('name', 'John Doe');
map.set('age', 30);</code>

Traverse the Map and print the key-value pairs:

<code class="javascript">map.forEach((value, key) => {
  console.log(`Key: ${key}, Value: ${value}`);
});
// 输出：
// Key: name, Value: John Doe
// Key: age, Value: 30</code>

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