JavaScript 中数字字符的表单验证
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Form validation of numeric characters in JavaScript
提问by Igor Novoselov
I would like to perform form validation using JavaScript to check for input field only to contain numeric characters.So far, the validation checks for the field not being empty - which works fine.However, numeric characters validation is not working.I would be grateful for any help.Many thanks.
我想使用 JavaScript 执行表单验证以检查仅包含数字字符的输入字段。到目前为止，该字段的验证检查不是空的 - 工作正常。但是，数字字符验证不起作用。我将不胜感激任何帮助。非常感谢。
<script type="text/javascript">
//form validation
function validateForm()
{
var x=document.forms["cdp_form"]["univer_number"].value
if (x==null || x=="")
{
alert("University number (URN) field must be filled in");
cdp_form.univer_number.focus();
return false;
}
else if (is_valid = /^[0-9]+$/.test(x))
{
alert("University number (URN) field must have numeric characters");
cdp_form.univer_number.focus();
return false;
}
}
</script>
<input type ="text" id="univer_number" maxlength="7" size="25" name="univer_number" />
采纳答案by mVChr
You need to test for the negation of the RegExp because you want the validation to alert upon failure, so just add !in front of it:
您需要测试 RegExp 的否定，因为您希望验证在失败时发出警报，因此只需!在其前面添加：
else if (is_valid = !/^[0-9]+$/.test(x))
回答by Oded
Your test condition is a bit strange:
你的测试条件有点奇怪：
else if (is_valid = /^[0-9]+$/.test(x))
Why have the redundant comparison to is_valid? Just do:
为什么有多余的比较is_valid？做就是了：
else if (/^[0-9]+$/.test(x))
Though the regex you are using will match numerals and only numerals - you need to change it to match anything that is nota numeral - like this /^[^0-9]+$/.
尽管您使用的正则表达式将匹配数字并且仅匹配数字 - 您需要更改它以匹配任何不是数字的东西- 就像这样/^[^0-9]+$/。
Better yet, get rid of the regex altogether and use IsNumeric:
更好的是，完全摆脱正则表达式并使用IsNumeric：
else if (!IsNumeric(x))
回答by Mikecito
Rather than using Regex, if it must only be numerals you can simply use IsNumeric in Javascript.
而不是使用正则表达式，如果它必须只是数字，你可以简单地在 Javascript 中使用 IsNumeric。
IsNumeric('1') => true;
IsNumeric('145266') => true;
IsNumeric('abc5423856') => false;
回答by Egor
You need invert your regular expression (add ^ inside [0-9]):
您需要反转正则表达式（在 [0-9] 内添加 ^）：
/^[^0-9]+$/
回答by Don
Your pattern will still accept this input <b>#@$@#123or ad!@#12<b>. Use this pattern I created:
您的模式仍将接受此输入<b>#@$@#123或ad!@#12<b>. 使用我创建的这个模式：
/[a-zA-Z-!@#$%^&*()_+\=\[\]{};':"\|,.<>\/?]/
This pattern will check if it is alphabetic and special characters.
此模式将检查它是否是字母和特殊字符。
回答by Donnie
On your line that says else if (is_valid = /^[0-9]+$/.test(x)), you're doing a simple assignment instead of testing that it is actually matching the regex.
在你说的那一行else if (is_valid = /^[0-9]+$/.test(x))，你正在做一个简单的分配，而不是测试它实际上是否与正则表达式匹配。
回答by Dorothy Kerrin Ryan
I know this is an old post but I thought I'd post what worked for me. I don't require the field to be filled at all but if it is it has to be numerical:
我知道这是一个旧帖子，但我想我会发布对我有用的内容。我根本不需要填写该字段，但如果是，则必须是数字：
function validateForm()
{
var x=document.forms["myformName"]["myformField"].value;
if (/[^0-9]+$/.test(x))
{
alert("Please enter a numerical amount without a decimal point");
myformName.myformField.focus();
return false;
}
}
