确保用户以JavaScript格式提交的邮政编码不能少于5个数字 [英] Making sure that a user can't submit less than 5 numbers for zip code in a JavaScript form

问题描述

我正在构建注册表，我需要一种防止用户提交少于5个邮政编码的方法.当我完全注释掉其他选项的尝试时，其他功能(确保用户不会提交任何字母)起作用.我在最后使用return false，以便表单不会提交，并且我可以测试错误的输入.很抱歉缺少jsfiddle-出于某种原因，它不会让我提交表单(我是菜鸟，所以可能是原因).这是我的代码段:

I am building a registration form and I need a way of preventing users from submitting less than 5 numbers for the zip code. When I comment out my attempt for the else if entirely, the other function (making sure that users won't submit any letters) works. I am using return false at the end so that the form won't submit and I can test for bad input. Sorry for the lack of jsfiddle - it wouldn't let me submit forms for some reason (I am a noob, so that may be the reason). Here's a snippet of my code:

HTML:

<form name="reg" onSubmit="return formValidation();">    
<p>Zip Code: <input type="text" id="zip" maxlength="5" name="zip"></p>
<input type="submit" id="submitbutton" name="submitbutton" value="Submit" />
<div id="msg"></div> 
</form>

JS:

function formValidation()  
{  
    var zip = document.reg.zip; 
    allnumeric(zip);

function allnumeric(zip)
{   
    var numbers = /^[0-9]+$/;  
    if(zip.value.match(numbers))  
    {  
        document.getElementById("msg").innerHTML=("OK ✓");
        msg.style.color="green";
    }  
    else if (zip.numbers < 5) /*DOES NOT COMPUTE*/
    {
        msg.innerHTML=("Has to be 5 numbers.");
        msg.style.color="red";
    }
    else
    {  
        msg.innerHTML=("Numbers only please.");
        msg.style.color="red";
    }  
};  
    return false;
};

推荐答案

您要的是zip.value.length，而不是zip.numbers.

您还可以使用正则表达式来完成整个工作:

You can also do the whole thing with the regex:

var numbers = /^\d{5}$/;  
if(zip.value.match(numbers))  
{  
    document.getElementById("msg").innerHTML=("OK ✓");
    msg.style.color="green";
}  
else
{  
    msg.innerHTML=("Numbers only please.");
    msg.style.color="red";
} 

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