数组的合并 总结的几种方法

var a=[0,1];
var b=[2,3,4];
 
for(var i=0;i<b.length;i++){
      a.push(b[i]) 
}
 
console.log(a);    //[0,1,2,3,4]

var a = [101,102,103]
var b = [‘a‘,‘b‘,‘c‘]
var c = a.concat(b)            //concat方法    返回新数组
console.log(c)                //[101, 102, 103, "a", "b", "c"]

var a = [101,102,103]
var b = [‘a‘,‘b‘,‘c‘]
a.push.apply(a, b)                 //合并,不产生新数组
console.log(a)                      //[101, 102, 103, "a", "b", "c"]

var a = [101,102,103]
var b = [‘a‘,‘b‘,‘c‘]
var c = [...a,...b]            // 扩展运算符的方法    产生一个新数组
console.log(c)                 // [101, 102, 103, "a", "b", "c"]