<view wx:for="{{array}}">
  {{index}}: {{item.message}}
</view>

Page({
  data: {
    array: [{
      message: 'foo',
    }, {
      message: 'bar'
    }]
  }
})

<view wx:for="{{array}}" wx:for-index="idx" wx:for-item="itemName">
  {{idx}}: {{itemName.message}}
</view>

<view wx:for="{{[1, 2, 3, 4, 5, 6, 7, 8, 9]}}" wx:for-item="i">
  <view wx:for="{{[1, 2, 3, 4, 5, 6, 7, 8, 9]}}" wx:for-item="j">
    <view wx:if="{{i <= j}}">
      {{i}} * {{j}} = {{i * j}}
    </view>
  </view>
</view>

<block wx:for="{{[1, 2, 3]}}">
  <view> {{index}}: </view>
  <view> {{item}} </view>
</block>

<switch wx:for="{{objectArray}}" wx:key="unique" style="display: block;"> {{item.id}} </switch>
<button bindtap="switch"> Switch </button>
<button bindtap="addToFront"> Add to the front </button>

<switch wx:for="{{numberArray}}" wx:key="*this" style="display: block;"> {{item}} </switch>
<button bindtap="addNumberToFront"> Add to the front </button>

Page({
  data: {
    objectArray: [
      {id: 5, unique: 'unique_5'},
      {id: 4, unique: 'unique_4'},
      {id: 3, unique: 'unique_3'},
      {id: 2, unique: 'unique_2'},
      {id: 1, unique: 'unique_1'},
      {id: 0, unique: 'unique_0'},
    ],
    numberArray: [1, 2, 3, 4]
  },
  switch: function(e) {
    const length = this.data.objectArray.length
    for (let i = 0; i < length; ++i) {
      const x = Math.floor(Math.random() * length)
      const y = Math.floor(Math.random() * length)
      const temp = this.data.objectArray[x]
      this.data.objectArray[x] = this.data.objectArray[y]
      this.data.objectArray[y] = temp
    }
    this.setData({
      objectArray: this.data.objectArray
    })
  },
  addToFront: function(e) {
    const length = this.data.objectArray.length
    this.data.objectArray = [{id: length, unique: 'unique_' + length}].concat(this.data.objectArray)
    this.setData({
      objectArray: this.data.objectArray
    })
  },
  addNumberToFront: function(e){
    this.data.numberArray = [ this.data.numberArray.length + 1 ].concat(this.data.numberArray)
    this.setData({
      numberArray: this.data.numberArray
    })
  }
})

<view wx:for="array">
  {{item}}
</view>

<view wx:for="{{['a','r','r','a','y']}}">
  {{item}}
</view>

<view wx:for="{{[1,2,3]}} ">
  {{item}}
</view>

<view wx:for="{{[1,2,3] + ' '}}" >
  {{item}}
</view>