JavaScript has a strange naming history. For its initial release in 1995 as part of Netscape Navigator, Netscape labeled their new language LiveScript, before renaming it to JavaScript a year later, hoping to capitalize on Java’s popularity at the ti
二 .字符串扩展 1.传统上,JavaScript只有indexOf方法,可以用来确定一个字符串是否包含在另一个字符串中.ES6又提供了三种新方法. includes():返回布尔值,表示是否找到了参数字符串. startsWith():返回布尔值,表示参数字符串是否在源字符串的头部. endsWith():返回布尔值,表示参数字符串是否在源字符串的尾部. var s = 'Hello world!'; console.log(s.startsWith('Hello')); // true co
1.数组循环 介绍数组循环之前,先回顾一下ES5数组的循环 (1)数组遍历(代替普通的for):arr.forEach(callback(val,index,arr){todo}) //val是数组的当前项,index是数组的键名(下标),arr是整个数组 let arr = ['today','tomorrow','the day after tommrrow','three days from now']; arr.forEach(function(val,index,arr){ conso
