正则表达式 RegExp 与 JavaScript API s.match(reg)
// 字符 var s = "The quick fox jumps over a lazy dog."; var reg = new RegExp("o", "g");// 或 var reg = /o/g; var arr = s.match(reg); console.log(arr.length);// 3 // 字符串 var s = "The quick fox jumps over a lazy dog."; var reg = new RegExp("fox", "g"); var arr = s.match(reg); console.log(arr.length);// 1