> 用于拼接字符串 ${} `JavaScript let a = 'Hello' console.log(${a} World) console.log(a + ' World') ` 2、Set,Map `javascript const grade = new Map() .set("A", "90-100") .s ...
> 用于拼接字符串 ${} `JavaScript let a = 'Hello' console.log(${a} World) console.log(a + ' World') ` 2、Set,Map `javascript const grade = new Map() .set("A", "90-100") .s ...
`javascript !(function (e, t, a) { function r() { for (var e = 0; e < s.length; e++) s[e].alpha <= 0 ? (t.body.removeChild(s[e].el), s.splice(e, 1)) : (s[e].y-- ...
> ### Array.unshift() / Array.push() 向数组首位 / 末尾添加一个或多个元素; 返回新的数组长度; 改变原数组; `javascript let arr1 = [1, 2, 3]; arr1.unshift(0); console.log(arr1); // [0,1,2,3] let arr2 = [1, 2 ...