Only accept number from 1 to 9 Using JavaScript

Question

Would like to know how to only accept number to be entered into inputbox from 1 to 9 and if entered for example 0 give alert message, sorry not a valid number.

please check my function that i have done so far, but not working.. thank you

<input name="number1" type="text" size="1" id="number1"onkeyup="doKeyUpValidation(this)/>

doKeyUpValidation(text){
var validationRegex = RegExp(/[-0-9]+/, "g");
if(!validationRegex.match(text.value)
{
 alert('Please enter only numbers.');
}

Seriously? You say `0-9` and expect it to reject `0`?! Not to mention that the HTML is invalid and the JS is (at least) missing a brace. — Quentin, May 16 '11 at 14:52
He says `[-0-9]`. Maybe s/he expected it to reject based on the leading `-`, as if it were a 'not inclusive' syntax. Which it isn't; the regex was wrong. — Katie Kilian, May 16 '11 at 14:57
Yeah, voted the above comment up (from -1) - but also the question itself, to remove the -1. Let's not be TOO harsh, guys. — Mörre, May 16 '11 at 14:57
I wish people would vote based on "Is this question useful?" rather then "Does this question deserve to be considered (un)useful by that number of people?" (And remember that you get more points for an upvote then you lose for a downvote, so it isn't a balancing act) — Quentin, May 16 '11 at 15:00
...and by the way, PLEASE DON'T DO THIS. It is VERY bad style to issue a very intrusive modal "alert" box for such a minor data input problem. You should simply add a text (bold or red) next to the input box, but opening a modal dialog box is bad. One should not use "alert" and those other modal dialogs from the very early Javascript days of the 1990s at all any more, actually. — Mörre, May 16 '11 at 15:02
@David Dorward: Useful to whom? This IS useful for beginners. Don't try to impose YOUR standards. I have a vote too - and I used it. Get over it. — Mörre, May 16 '11 at 15:03

score 1 · Answer 1 · answered May 16 '11 at 14:55

1

You're missing a closing quote at the end of your onkeyup attribute, and as David mentions, you need to change your regex string to /[1-9]/

answered May 16 '11 at 14:55

n00dle

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Katie Kilian · Answer 2 · 2011-05-16T15:55:26.363

1

You were pretty close. Try this:

function doKeyUpValidation(text) {
    var validationRegex = RegExp(/[1-9]+/, "g");  // The regex was wrong
    if( !validationRegex.match(text.value) )
    {
        alert('Please enter only numbers.');
    }
} // this was missing before

edited May 16 '11 at 15:55

answered May 16 '11 at 14:55

Katie Kilian

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You're missing the `function` keyword, and a `)` after the if statement. – gen_Eric May 16 '11 at 15:37

score 0 · Answer 3 · answered May 16 '11 at 15:02

Your HTML is slightly wrong, it should be:

<input name="number1" type="text" size="1" id="number1" onkeyup="doKeyUpValidation(this)"/>

You need a space between each attribute, and each attribute needs to be quoted.

Also, your JavaScript has a few errors. It should be:

function doKeyUpValidation(text) {
    var validationRegex = /[1-9]/g;
    if (!validationRegex.test(text.value)) {
        alert('Please enter only numbers.');
    }
}

You need the function keyword to make doKeyUpValidation a function. Also, your regex was a little off.

Demo: http://jsfiddle.net/EqhSS/10/

Only accept number from 1 to 9 Using JavaScript

3 Answers3