字符串处理方法
var str = '2019-12-27';
var arr = str.split('-');//将-切掉['2019','12','27']
var arr2 = str.split('');//将每个字符分开['2','0','1','9','1','2','2','7']
var str2 = '#div1';
var str3 = '.div1';
var str4 = 'str2.charAt(0)';//#
if (str4 == '#'){
console.log('id选择器');
}
var str5 = 'Microsoft Yahei';
var num = str5.indexOf('Yahei');//10
var num2 = str5.indexOf('xihei');//-1
var str6 = str5.substring(10,15);//从10开始从15结束 包括开始不包括结束Yahei
var str6 = str5.substring(10);//从10开始到结尾Yahei
console.log(str6.toUpperCase());//全转大写YAHEI
console.log(str6.toLowerCase());//全转小写 yahei
字符串反转
1、split字符串转成数组
2、reverse数组反转
3、join数组转成字符串
var sTr = '123asd7988asdfe21';
var str2 = sTr.split('').reverse().join('');//12efdsa8897dsa321
console.log(str2)
