js清空数组的方法

1、给数组的length赋值为0；

 let arr = [1, 2, 3]
      console.log(arr) // [1,2,3]
      arr.length = 0
      console.log(arr) //[]

2、通过数组splice()方法；

 let arr = [1, 2, 3]
      console.log(arr) // [1,2,3]
      arr.splice(0, arr.length)
      console.log(arr) //[]

3、赋值为[ ]

 let arr = [1, 2, 3]
      console.log(arr) // [1,2,3]
      arr =[]
      console.log(arr) //[]