函数来确定一个字符串从另一个只包含字符 [英] Function to determine if a string contains characters only from another

问题描述

我工作的HTML标签输入验证功能。我已经在特定的输入和含有允许的字符字符串的值的字符串。

I'm working on a validation function for html input tags. I've the string of the value of the particular input and the string containing the allowed characters.

var allowed = 'abcdefghijklmnopqrstuvwxyz";
var value = element.value;

我想编写一个函数，以确定是否值仅包含允许的 字符串的字符。我在寻找一个直接的和简单的解决方案。
任何想法？

I'd like to write a function to determine if the value contains character only from the allowed string. I'm looking for a straight-forward and simple solution. Any ideas?

推荐答案

是的，你可以使用正则表达式

Yes you can use regex

function alphanumeric(inputtxt)  
{   
    var letters = /^[a-z]+$/;  
    //if you want upper and numbers too 
    //letters = /^[A-Za-z0-9]+$/;
    //if you only want some letters
    // letters = /^[azertyuiop]+$/;
    if(inputtxt.value.match(letters))  
    {  
        alert('Your registration number have accepted : you can try another');  
        document.form1.text1.focus();  
        return true;  
    }  
    else  
    {  
        alert('Please input alphanumeric characters only');  
        return false;  
    }  
} 

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