前端复习--正则

var str = 'abcabcad';
var re = /a(?=d)/g;  //只匹配a后面接d的a
str = str.replace(re,'*');
//"abcabc*d"

var str = 'abcabcad';
var re = /a(?=bc)/g;  //只匹配a后面接bc的a
str = str.replace(re,'*');
//"*bc*bcad"

var str="cccabbammmm";
var re = /(\w)(\w)\2\1/g;
str = str.replace(re,"*")    //会匹配str里的abba和mmmm，因为他们都符合这种结构
//"ccc**"