exec方法為正規表示式相符的文字搜尋字串。如果找到匹配，則傳回結果數組; 否則，返回null。
文法
RegExpObject.exec( string );
以下是參數的詳細資訊：
傳回值:
範例：
<html>
<head>
<title>JavaScript RegExp exec Method</title>
</head>
<body>
<script type="text/javascript">
var str = "Javascript is an interesting scripting language";
var re = new RegExp( "script", "g" );
var result = re.exec(str);
document.write("Test 1 - returned value : " + result);
re = new RegExp( "pushing", "g" );
var result = re.exec(str);
document.write("<br />Test 2 - returned value : " + result);
</script>
</body>
</html>
這將產生以下結果：
Test 1 - returned value : script Test 2 - returned value : null
