Regex in javascript always matches only 1 character?
It seems like no matter what input I give this, it always only matches 1 character. m.index
is always 0 on a match and m.length
is always 1. what am I doing wrong here? I have tried it at(and ripped off some code from) http://www.regular-expressions.info/javascriptexample.html and it works as expected there and matches an entire number.
You can see a live example here http://jsbin.com/aqobe
<html>
<head>
<script type="text/javascript">
function __numberBox__correctFormat(text,allow_float){
var r;
if(allow_float){
r=/\$?[\d,\.\W]+/;
}else{
r=/\$?[\d,\W]+/;
}
var m=r.exec(text);
if(m==null){
return false;
}
alert(m.index); alert(m.length);
if(m.index!=0 || m.length!=text.length){ //must match the whole string
return false;
}
return true;
}
</script>
</head>
<body>
Enter your name: <input type="text" id="fname" onchange="
if(__numberBox__correctFormat(this.value,true)){
alert('tis true');
}else{
alert('tis false');
}" />
</body>
</htm开发者_StackOverflow社区l>
Note I'm wanting for it to accept this input
1234 532,134 $123 493.29
The return value of Regex.exec
is always an array containing the list of matches. In your case, the regex will match the whole string so the return value is an array with 1 element that contains the match.
/\$?[\d,\.\W]+/.exec("$493.29")
["$493.29"]
You can use the following code:
var r;
if(allow_float){
r=/^\$?\d[\d,\.\W]+$/;
} else {
r = /^\$?\d[\d,\W]+$/;
}
return r.test(text);
EDIT: Reject single $
.
The (unescaped) ^
and $
characters match the beginning and of the string, respectively. Therefore, this will only return true
if it matches the entire string.
By the way, your regex is very liberal; it matches strings like $1!2@3#4$5%6^7&8*9(0),.1,.4
.
I recommend using Javascript's built-in number-parsing methods, like this:
function __numberBox__correctFormat(text,allowFloat){
if (text.charAt(0) === '$')
text = text.substring(1);
return (allowFloat ? parseFloat : parseInt)(text.replace(',', ''), 10);
}
Without the ternary cleverness, that would look like this:
text = text.replace(',', '');
if(allowFloat)
return parseFloat(text);
return parseInt(text, 10);
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