小程序：使用 wx:key 提升 wx:for 的渲染效率

<block wx:for="{{languages}}" wx:for-item="language" wx:key="id">
  <text class="log-item">{{ language.id }} . {{ language.name }}</text>
</block>

data: {
  languages: [
    {id: 1, name: &#39;php&#39;},
    {id: 4, name: &#39;javascript&#39;},
    {id: 3, name: &#39;golang&#39;},
    {id: 2, name: &#39;python&#39;},
    {id: 5, name: &#39;java&#39;},
  ],
},

data: {
  languages: [
    {id: 1, name: 'php'},
    {id: 4, name: 'javascript'},
    {id: 3, name: 'golang'},
    {id: 2, name: 'python'},
    {id: 5, name: 'java'},
  ],
},

click: function () {
	let language = {id: 5, name: 'kotlin'}
	let languages = this.data.languages
	languages.push(language)

	this.setData({
		languages: languages
	})
}