Simple use of promise method

es6 Of promise It's easy to use , Knowing the usage scenario is enough for daily use , Here are just a few notes , Record resolve and reject Use

effect ：

there resolve,reject It literally means to go when you succeed resolve, Failure to walk reject; stay resolve,reject Adding data can be done in then From the callback function . We need to pay attention to then Take two functions , The first is to deal with resolve The second is reject Of

// promise Method 
    testPromise() {
    
      var _Prom = new Promise(function(resolve, reject) {
    
        var num = Math.ceil(Math.random() * 10) // Generate 1-10 The random number 
        if (num > 5) {
    
          resolve(' Greater than 5 go resolve')
        } else {
    
          reject(' Less than 5 go reject')
        }
      })
      return _Prom
    },
    test() {
    
      this.testPromise().then(
        res => {
    
          console.log(res)
        },
        err => {
    
          console.log(err)
        }
      )
    }