<html><body><h1>JavaScript 正则表达式</h1><p>exec() 方法测试（检索）字符串中的匹配项：</p><p id="demo"></p><script>let text = "Hello world!";// 查找 "Hello"let result1 = /Hello/.exec(text);// 查找 "W3School"let result2 = /W3School/.exec(text);document.getElementById("demo").innerHTML =result1 + "<br>" + result2;</script></body></html>