Regular expression JavaScript

Question

I have modal pop up for adding data, I have to validate textbox using JavaScript regular expression for numeric values only. I want to enter only numbers in text box, so tell me what is proper numeric regular expression for that?

Is is integers only or do you want to have stuff like floats, rationals, scientific notation or complex? — Jakub Hampl, Mar 24 '11 at 13:57
And, actually, I messed up the pattern. It should be `^\d+(?:\.\d+)?$` (The final * would allow `1.2.3.4`, which wouldn't be a valid number.) — Brad Christie, Mar 24 '11 at 14:15
Jakob's question is worth repeating: What, exactly, is a "numeric value"? See: [What’s a Number?](http://stackoverflow.com/questions/4246077/simple-problem-with-regular-expression-only-digits-and-commas/4247184#4247184) — ridgerunner, Mar 24 '11 at 17:24

score 2 · Answer 1 · answered Mar 24 '11 at 15:04

2

Why not using isNaN ? This function tests if its argument is not a number so :

if (isNaN(myValue)) {
   alert(myValue + ' is not a number');
} else {
   alert(myValue + ' is a number');
}

answered Mar 24 '11 at 15:04

Toto

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isNAN will report a number for '0xabcd' since it is a valid hexadecimal number. – HBP Mar 24 '11 at 16:31

score 1 · Answer 2 · answered Mar 24 '11 at 13:56

1

You can do it as simple as:

function hasOnlyNumbers(str) {
 return /^\d+$/.test(str);
}

Working example: http://jsfiddle.net/wML3a/1/

answered Mar 24 '11 at 13:56

Martin Jespersen

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score 0 · Answer 3 · edited Mar 24 '11 at 13:56

0

^\d+$ of course if you want to specify that it has to be at least 4 digits long and not more than 20 digits the pattern would then be => ^\d{4,20}$

edited Mar 24 '11 at 13:56

Jakub Hampl

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answered Mar 24 '11 at 13:55

pythonian29033

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Regular expression JavaScript

3 Answers3