将一个数组插入到另一个数组指定位置
let a = [1,2,3,7,8,9] let b = [4,5,6] let insertIndex = 3 a.splice.apply(a,Array.prototype.concat(insertIndex,0,b)) //[1,2,3,4,5,6,7,8,9]
let a = [1,2,3,7,8,9] let b = [4,5,6] let insertIndex = 3 a.splice.apply(a,Array.prototype.concat(insertIndex,0,b)) //[1,2,3,4,5,6,7,8,9]