空输入字段的JavaScript验证

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空输入字段的JavaScript验证

javascript

问候，我有这个输入字段， <input name="question"/>我想在单击提交按钮时调用IsEmpty函数。

我尝试了下面的代码，但是没有用。有什么建议吗？

<html>



<head>

  <title></title>

  <meta http-equiv="Content-Type" content="text/html; charset=unicode" />

  <meta content="CoffeeCup HTML Editor (www.coffeecup.com)" name="generator" />

</head>



<body>





  <script language="Javascript">

    function IsEmpty() {



      if (document.form.question.value == "") {

        alert("empty");

      }

      return;

    }

  </script>

  Question: <input name="question" /> <br/>



  <input id="insert" onclick="IsEmpty();" type="submit" value="Add Question" />



</body>



</html>

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2020-05-01

共1个答案

小编典典

<script type="text/javascript">

  function validateForm() {

    var a = document.forms["Form"]["answer_a"].value;

    var b = document.forms["Form"]["answer_b"].value;

    var c = document.forms["Form"]["answer_c"].value;

    var d = document.forms["Form"]["answer_d"].value;

    if (a == null || a == "", b == null || b == "", c == null || c == "", d == null || d == "") {

      alert("Please Fill All Required Field");

      return false;

    }

  }

</script>



<form method="post" name="Form" onsubmit="return validateForm()" action="">

  <textarea cols="30" rows="2" name="answer_a" id="a"></textarea>

  <textarea cols="30" rows="2" name="answer_b" id="b"></textarea>

  <textarea cols="30" rows="2" name="answer_c" id="c"></textarea>

  <textarea cols="30" rows="2" name="answer_d" id="d"></textarea>

</form>

2020-05-01