Vue开发之watch监听数组、对象、变量操作分析

本文实例讲述了Vue开发之watch监听数组、对象、变量操作。分享给大家供大家参考,具体如下:

1.普通的watch

data() {
  return {
    frontPoints: 0
  }
},
watch: {
  frontPoints(newValue, oldValue) {
    console.log(newValue)
  }
}

2.数组的watch:深拷贝

data() {
  return {
    winChips: new Array(11).fill(0)
  }
},
watch: {
  winChips: {
    handler(newValue, oldValue) {
      for (let i = 0; i < newValue.length; i++) {
        if (oldValue[i] != newValue[i]) {
          console.log(newValue)
        }
      }
    },
    deep: true
  }
}

3.对象的watch

data() {
  return {
    bet: {
      pokerState: 53,
      pokerHistory: 'local'
    }
  }
},
watch: {
  bet: {
    handler(newValue, oldValue) {
      console.log(newValue)
    },
    deep: true
  }
}

4.对象的具体属性的watch:

data() {
  return {
    bet: {
      pokerState: 53,
      pokerHistory: 'local'
    }
  }
},
computed: {
  pokerHistory() {
    return this.bet.pokerHistory
  }
},
watch: {
  pokerHistory(newValue, oldValue) {
    console.log(newValue)
  }
}

希望本文所述对大家vue.js程序设计有所帮助。