Question

提交按钮应弹出一条警告消息，说明当用户输入错误时，邮编和邮政编码上的图案是错误的。但我似乎无法使其发挥作用。我不想使用＆＃34; pattern =＆＃34;通知。我想显示一个警告框。我需要使用RegExp方法。有什么想法吗？

这是我的代码：

                <script>
                function validation(){
                  var icn = document.getElementById("icno").value;
                  var postcode = document.getElementById("pstcode").value;
                  var regexp = new RegExp(icn,"\d{6}-\d{2}-\d{4}");
          var regexp1 = new RegExp(postcode,"[0-9]{5}");

                  if (regexp.exec(icn)){
            return true;
                  }
                  else{
            alert("Please enter your IC correctly")
                  }

          if (regexp1.exec(postcode)){
            return true;
                  }
                  else{
            alert("Please enter your postcode correctly")
                  }
                }
                </script>
            </body>
    </html>

Answer 1

如果您想使用RegExp和.exec，请尝试以下操作：

＆＃13;

function validation() {
  var icn = document.getElementById("icno").value;
  var postcode = document.getElementById("pstcode").value;
  var regexp = new RegExp(/\d{6}-\d{2}-\d{4}/);
  var regexp1 = new RegExp(/[0-9]{5}/);

  if (regexp.exec(icn) !== null) {
    return true;
  } else {
    alert("Please enter your IC correctly")
  }

  if (regexp1.exec(postcode) !== null) {
    return true;
  } else {
    alert("Please enter your postcode correctly")
  }
}

＆＃13;

<form id="myForm" onsubmit="validation()">
  <fieldset>
    <legend>Regular Expression</legend>

    <label for="name">Name</label>
    <input type="text" id="name" size="30" placeholder="Enter name.">
    </br>
    </br>

    <label for="icno">IC No</label>
    <input type="text" id="icno" size="15" placeholder="E.g. 889601-11-6575">
    </br>
    </br>

    <label for="address">Address 1</label>
    <input type="text" id="address" size="30" placeholder="Address 1">
    </br>
    </br>

    <label for="address">Address 2</label>
    <input type="text" id="address" size="30" placeholder="Address 2">
    </br>
    </br>

    <label for="postcode">Postcode</label>
    <input type="text" id="pstcode" size="8" placeholder="E.g 21030">
    </br>
    </br>

    <input type="submit" value="Submit" id="btnSubmit">
  </fieldset>
</form>

＆＃13;

但我建议您使用.test，这很简单：

function validation() {
   var icn = document.getElementById("icno").value;
   var postcode = document.getElementById("pstcode").value;

   if (/\d{6}-\d{2}-\d{4}/.test(icn)) {
     return true;
   } else {
     alert("Please enter your IC correctly")
   }

   if (/[0-9]{5}/.test(postcode)) {
     return true;
   } else {
     alert("Please enter your postcode correctly")
   }
 }

Answer 2

定义RegExp时，可以传递2个参数：1）模式，2）标志。您传递了包含文本的变量作为第一个参数进行搜索，并将模式作为第二个参数传递。

第二个问题是你期望一个完整的字符串匹配，所以，你错过了锚点（^ - 字符串的开头 - 和$ - 字符串的结尾。）

var regexp = /^\d{6}-\d{2}-\d{4}$/;
var regexp1 = /^\d{5}$/;

然后更正if块：

var icn_check = regexp.test(icn);
var pcode_check = regexp1.test(postcode);

if (icn_check && pcode_check){      // Only return true if both fields are valid
   return true;
}
else {
  if (!pcode_check) {                                // If post code is invalid
    alert("Please enter your postcode correctly");
  }
  if (!icn_check) {                                  // If ICN is invalid
    alert("Please enter your IC correctly");
  }
}

使用RegExp#test()代替exec()来检查字符串是否与正则表达式匹配。

请参阅the JS fiddle demo

function validation() {
  var icn = document.getElementById("icno").value;
  var postcode = document.getElementById("pstcode").value;
  var regexp = /^\d{6}-\d{2}-\d{4}$/;
  var regexp1 = /^\d{5}$/;
  var icn_check = regexp.test(icn);
  var pcode_check = regexp1.test(postcode);
  if (icn_check && pcode_check) {
    return true;
  } else {
    if (!pcode_check) {
      alert("Please enter your postcode correctly");
    }
    if (!icn_check) {
      alert("Please enter your IC correctly");
    }
  }
}

<form id="myForm" onsubmit="validation()">
  <fieldset>
    <legend>Regular Expression</legend>
    <label for="name">Name</label>
    <input type="text" id="name" size="30" placeholder="Enter name.">
    <br/>
    <br/>

    <label for="icno">IC No</label>
    <input type="text" id="icno" size="15" placeholder="E.g. 889601-11-6575">
    <br/>
    <br/>

    <label for="address">Address 1</label>
    <input type="text" id="address" size="30" placeholder="Address 1">
    <br/>
    <br/>

    <label for="address">Address 2</label>
    <input type="text" id="address" size="30" placeholder="Address 2">
    <br/>
    <br/>

    <label for="postcode">Postcode</label>
    <input type="text" id="pstcode" size="8" placeholder="E.g 21030">
    <br/>
    <br/>

    <input type="submit" value="Submit" id="btnSubmit">
  </fieldset>
</form>

Javascript - 如何使用RegExp识别模式

2 个答案: