ES6 从入门到精通 # 13：数组的扩展方法二

Posted 2022-08-11 凯小默

说明

ES6 从入门到精通系列（全23讲）学习笔记。

遍历器

entries()，keys()，values()， 返回一个遍历器，可以使用 for···of 循环进行遍历

• keys()：对值遍历
• values()：对键值对遍历
• entries()：对键名遍历

console.log(["k", "a", "i", "m", "o"].keys());
console.log(["k", "a", "i", "m", "o"].values());
console.log(["k", "a", "i", "m", "o"].entries());

for (let key of ["k", "a", "i", "m", "o"].keys()) 
	console.log(key);

for (let value of ["k", "a", "i", "m", "o"].values()) 
	console.log(value);

for (let [key, value] of ["k", "a", "i", "m", "o"].entries()) 
	console.log(key, value);

let kaimo = ["k", "a", "i", "m", "o"].entries();
console.log(kaimo.next().value)
console.log(kaimo.next().value)
console.log(kaimo.next().value)
console.log(kaimo.next().value)
console.log(kaimo.next().value)
console.log(kaimo.next().value)

includes

includes() 返回一个布尔值，表示某个数组是否包含给定的值

console.log([1,2,3].indexOf(1) > -1)
console.log([1,2,3].includes(1))