/** * 扩展运算符(...) spread */ var arr = [1,2,3,4,5,6]; var b = [...arr]; b[0] = 8; console.log(arr,'arr'); console.log(b,'b'); var a = [1,2,3]; console.log(...a,'...a'); var b = [2,3,4]; var c = [...a,...b]; // var c = a.concat(b); console.log(c,'c'); // 类数组 /** *1.JavaScript 常见的类数组:arguments *2.获取Dom元素方法返回的结果(比如getElementsByTagName,getElementsByClassName,querySelectAll) */ // function fun1() { // console.log(arguments,'类') // } // fun1(1,2,3,4,5) // fun1(arr,'arr') let a1 = document.querySelectorAll("ul li"); console.log(a1,'a1') // 将类数组 转成数组 let news = [...a1]; console.log(news,'news'); news.push(121); console.log(news,'news');