Javascript 正则表达式的三个方法

The RegExp Object has 3 methods: test(), exec(), and compile().

<script type="text/javascript">
var patt1=/\d/
document.write(patt1.test("34a"));
</script>

页面输出是true

function validationRegExp(regex, inputStr, helpText, helpMessage){
  if(!regex.test(inputStr)){
     if(helpText != null)
       helpText.innerHTML = helpMessage; return false;
  }else{
     if(helpText != null)
       helpText.innerHTML = ""; return true;
  }    
}