源代码 ：
点击运行
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>开源教程(ossoft.cn)</title> </head> <body> <script> var str = "Is is the cost of of gasoline going up up"; var patt1 = /\b([a-z]+) \1\b/ig; document.write(str.match(patt1)); </script> </body> </html>
运行结果