如何只允许使用JavaScript的字母数字字符 [英] How To Only Allow Alpha Numeric Chars With JavaScript
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问题描述
一直在使用JavaScript,我想要做的只是允许传递字段中的某些字符 - az,AZ和0-9。
Been playing around with JavaScript, and what Im trying to do is only allow certain characters in the pass word field - a-z, A-Z and 0-9.
<form action="http://www.cknuckles.com/cgi/echo.cgi" method="get" name="logOn">
User Name:<br />
<input type="text" name="userName" size="25" /><br />
Password:<br />
<input type="password" name="pw" size="25" /><br />
<input type="submit" value="Log In" onClick="validate()"/>
</form>
以上是我的HTML,下面是我尝试用来验证它的JavaScript - 但它不是工作 - 任何线索。
Above is my HTML, and Below is my JavaScript I tried to use to validate it - but it doesnt work - any clues.
<script language="javascript">
document.logOn.onsubmit=validate;
function validate(){
var name=document.logOn.pw.value;
if(!name = "[a-zA-Z0-9]"){
alert("Your Password Cant Have Any Funky Things In It - Play It Straight!");
return false;
}
return true;
}
</script>
但这不起作用。我仍然可以将字符添加为*和[和{等。
But This isnt working. I can still put chars in like "*" and "[" and "{" etc.
任何想法?
推荐答案
你需要让你的条件测试一个正则表达式,而不是一个字符串:
You need to make your condition test a regexp, not a string:
if(!/^[a-zA-Z0-9]+$/.test(name)){ ...
含义:
-
^
- 行首 -
[a-zA-Z0-9] +
- 一个或多个字符/数字 -
$
- 行尾
^
-- start of line[a-zA-Z0-9]+
-- one or more characters/numbers$
-- end of line
或者您可以搜索反之,即任何不接受的字符:
or you could search for the inverse of that, which is "any non-accepted character":
if(/[^a-zA-Z0-9]/.test(name)){
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