HTML/JavaScript:提交时的简单表单验证 [英] HTML/JavaScript: Simple form validation on submit

问题描述

我正在尝试以最简单的方式验证我的表单，但不知何故它不起作用，当我单击提交时，它只会将我带到下一页而没有给出警报消息:

I'm trying to validate my form with the easiest way possible, but somehow it is not working and when I click submit it just takes me to the next page without giving the alert message:

HTML:

<form name="ff1" method="post" onsubmit="validateForm();">
    <input type="text" name="email" id="fremail" placeholder="[e-mail]" />
    <input type="text" name="title" id="frtitle" placeholder="Title" />
    <input type="text" name="url"   id="frurl"   placeholder="http://yourwebsite.com/" />

    <input type="submit" name="Submit" value="Continue" />
</form>

JavaScript:

JavaScript:

<script type="text/JavaScript">

function validateURL(url) {
    var reurl = /^(http[s]?://){0,1}(www.){0,1}[a-zA-Z0-9.-]+.[a-zA-Z]{2,5}[.]{0,1}/;
    return re.test(url);
}

function validateForm()
{
    // Validate URL
    var url = $("#frurl").val();
    if (validateURL(url)) { } else {
        alert("Please enter a valid URL, remember including http://");
    }

    // Validate Title
    var title = $("#frtitle").val();
    if (title=="" || title==null) { } else {
        alert("Please enter only alphanumeric values for your advertisement title");
    }

    // Validate Email
    var email = $("#fremail").val();
    if ((/(.+)@(.+){2,}.(.+){2,}/.test(email)) || email=="" || email==null) { } else {
        alert("Please enter a valid email");
    }
  return false;
}
</script>

这里也在 jsfiddle http://jsfiddle.net/CrLsR/

Here is also in jsfiddle http://jsfiddle.net/CrLsR/

推荐答案

您有几个错误.

首先，您必须从 HTML 标记中的函数返回一个值: <form name="ff1";方法=发布"onsubmit="return validateForm();">

First, you have to return a value from the function in the HTML markup: <form name="ff1" method="post" onsubmit="return validateForm();">

其次，在 JSFiddle 中，您将代码放在 onLoad 中，然后表单将无法识别它 - 最后，如果所有验证都成功，您必须从函数返回 true - 我在更新中修复了一些问题:

Second, in the JSFiddle, you place the code inside onLoad which and then the form won't recognize it - and last you have to return true from the function if all validation is a success - I fixed some issues in the update:

https://jsfiddle.net/mj68cq0b/

function validateURL(url) {
    var reurl = /^(http[s]?://){0,1}(www.){0,1}[a-zA-Z0-9.-]+.[a-zA-Z]{2,5}[.]{0,1}/;
    return reurl.test(url);
}

function validateForm()
{
    // Validate URL
    var url = $("#frurl").val();
    if (validateURL(url)) { } else {
        alert("Please enter a valid URL, remember including http://");
        return false;
    }

    // Validate Title
    var title = $("#frtitle").val();
    if (title=="" || title==null) {
        alert("Please enter only alphanumeric values for your advertisement title");
        return false;
    }

    // Validate Email
    var email = $("#fremail").val();
    if ((/(.+)@(.+){2,}.(.+){2,}/.test(email)) || email=="" || email==null) { } else {
        alert("Please enter a valid email");
        return false;
    }
  return true;
}

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