验证表单编号类型 Javascript

Validating Form Number Type Javascript

本文关键字：Javascript 类型 编号 表单 验证      更新时间：2023-09-26

嗨，我遇到了这个问题。在我的 html 代码中，我似乎无法验证我的输入类型"数字"。Iv'e 使用此代码来尝试验证它，但它不起作用 

function validateForm()
{
var x=document.forms["form_name"]["number_name"].value;
if (x==null || x=="")
  {
  alert("The following must be filled out");
  return false;
  }
}

我从一个验证输入类型"文本"而不是数字的网站中获取了这段代码。我正在尝试对我的完整 html 代码实现有效的"数字"验证。顺便说一句，这是我的表单示例：

<form action = "test.php" method = "post" onsubmit = "return validateForm()" name ="form_name">
<input type = "number" min = "0" placeholder = "0" name = "number_name" size = "2"/>

我想知道是否可以使用上面的 javascript valdiation 来验证数字形式，或者是否有更简单的方法可以做到这一点。

*

深入*我为我的第一个问题制作了一个快速的 html 代码，并制作了多种形式的"数字"。它不完整...我决定在实现整个表单的代码之前测试一个"数字"这是我到目前为止的代码：

<html>
    <head>
    <script language="javascript">
    function validateForm()
    {
    var x=document.forms["order"]["cappuccino_qty"].value;
    if (x >= 0 || x < 0);
    {
    alert("The following must be filled out");
    return false;
    }
    }
    </script>   
    <body>              
    <form action = "test.php" method = "post" onsubmit = "return validateForm()" name ="order">
                <label class = "field" for = "Cappucino">Cappuccino
                <input type = "number" min = "0" placeholder = "$3.75" name = "cappuccino_qty" size = "2"/><br>
                <label class = "field" for = "Espresso">Espresso
                <input type = "number" min = "0" placeholder = "$3.00" name = "espresso_qty" size = "2"/><br>
                <label class = "field" for = "Double Espresso">Double Espresso
                <input type = "number" min = "0" placeholder = "$4.25" name = "double_espresso_qty" size = "2"/><br>
                <label class = "field" for = "Flat White">Flat White
                <input type = "number" min = "0" placeholder = "$3.75" name = "flat_white_qty" size = "2"/><br>
                <label class = "field" for = "Latte">Latte  
                <input type = "number" min = "0" placeholder = "$3.50" name = "latte_qty" size = "2"/><br>
                <label class = "field" for = "Ice Coffee">Ice Coffee
                <input type = "number" min = "0" placeholder = "$2.50" name = "ice_qty" size = "2"/><br>
                <input type = "submit" value = "submit" name = "submit"/>
                <p>
       </form>
       </body>  
       </head>
       </Html>

更改

if (x==null || x=="")

自

if (/[^'d'.]/.test(x))

这将检查任何非数字或句点字符（假设您希望允许小数）。

[编辑]

请参阅更新的小提琴：http://jsfiddle.net/5UxGp/1/

一个简单的方法

function validateForm()
{
var x=document.forms["form_name"]["number_name"].value;
if (!(x >= 0) || !(x < 0))
  {
  alert("The following must be filled out");
  return false;
  }
}

顺便说一下，如果 0 是表单中的最小值

 function validateForm()
    {
    var x=document.forms["form_name"]["number_name"].value;
    if (!(x >= 0))
      {
      alert("The following must be filled out");
      return false;
      }
    }

您只是在测试变量是否为空或空，但是当您在其上输入字符时，它会跳出您的 if 语句。尝试使用此函数。如果需要，请参阅此处的参考：在 JavaScript 中验证十进制数 - IsNumeric（）。希望有帮助。

function isNumber(x) {
    return !isNaN(parseFloat(x)) && isFinite(x);
}
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