Vue中watch监听属性和对象的基本用法

data() { return { test: '123', test1:'', queryParams:{ userID:'', name:'dong' } }

    监听属性
    watch:{
        test:{
          immediate:true, // 初次就监听
          handler(newval,oldval){
            console.log('newval--------' + newval)
            console.log('oldval--------' + oldval)
            console.log('test1--------' + this.test1)
          }
    },

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```
 监听对象
  watch:{
    queryParams:{
      deep:true,
      immediate:true,
      handler:function(newval,oldval){
        if(newval){
          console.log('this.queryParams--------', oldval)
          console.log(this.queryParams)
        }
      }
    }
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