Regex not working in jquery for form validation
Question
I am runing the following jquery script:
<html>
<head>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$("#textThing").blur(function(){
var isNumber = $("#textThing").val().match(/^\d+/);
$("#p2").html(isNumber);
});
});
</script>
</head>
<body>
<input type="text" id="textThing" />
<p id="p2">Paragraph 2</p>
</body>
</html>
The problem is that the p2 never gives me anything when I deselect the input. What did I do wrong?
4 answers
solution1
1 ACCPTED 2012-06-21 03:59:38
You need to say:
$("#p2").html(isNumber == null ? "" : isNumber[0]);
instead of:
$("#p2").html(isNumber);
...because .match() returns an array if matched. See here: https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String/match
Here's a working version: http://jsfiddle.net/k45Ka/5/
solution2
1 2012-06-21 04:02:56
Working demo http://jsfiddle.net/r4VPZ/3/ or http://jsfiddle.net/r4VPZ/4/
You can see .match explaination above.
You can also use .toString with .html or .text api. You can do a null handling or look into isNaN http://www.w3schools.com/jsref/jsref_isnan.asp
Hope it helps, please let me know if I missed anything, cheers :)
Good read: http://api.jquery.com/html/ & http://api.jquery.com/text/
Match : What does .match returns : learning regex and jquery - what does .match return?
code
$(document).ready(function(){
$("#textThing").on("blur",function(){
var isNumber = $("#textThing").val().match(/^\d+/);
$("#p2").html(isNumber.toString());
// $("#p2").text(isNumber);
});
});
//var folioIsNumResult = $("#Folio").val().match(/^\d+/i);
solution3
1 2012-06-21 04:03:12
demo : http://jsfiddle.net/epinapala/TbCfc/
match returns null when the regex is not matched!
$(document).ready(function(){
$("#textThing").blur(function(){
var isNumber = $(this).val().match(/^\d+/);
if(isNumber == null){
var res = "not a number"
}else{
var res = "valid number";
}
$("#p2").html(res);
});
});
solution4
0 2012-06-21 03:57:54
You aren't creating any text values to put in if test passes or fails
DEMO http://jsfiddle.net/9MJNj/
$("#p2").html(isNumber ? 'Is number':'Is not');
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