a comparison in jquery

Question

I have this jquery function:

$(function() {

    $('.submitButton').click(function(){
        $('input').each(function() {
             if ($(this).attr('min')) {
                 if ($(this).val()<$(this).attr('min')){
                      $('#'+$(this).attr('id')+"_errMess").prepend(' Your data should be more than '+$(this).attr('min'));
                  }
              }
        });
    });
});

It seems that it checks only the first digit entered in the input. because for example when the value of 'min' attribute is 7, and the value entered in input is 10, it shows the error message (the if condition is true!!). although when i want it to alert value, it seems it knows the true and total value and returns 10.

alert($(this).val());

Can you please help me understand what is wrong?

Try comparing integers, and not strings, and see if that works! — adeneo, Dec 29 '12 at 05:53

LPD · Accepted Answer · 2012-12-29T06:02:13.540

1

The issue here is it is comparing '7' to '10' and not 7 to 10 [ASCII comparison character by character and not actual integer comparison]. Do parseInt() to the values and then compare, you should get desired results.

Change

$(this).val()<$(this).attr('min')

to

parseInt($(this).val())< parseInt($(this).attr('min'))

inside your if condition

ALso its better to extract the values to the variable and then perform the comparison.

edited Dec 29 '12 at 06:02

answered Dec 29 '12 at 05:52

LPD

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You should include a radix for those parseInt's ! – adeneo Dec 29 '12 at 06:11

score 1 · Answer 2 · answered Dec 29 '12 at 05:53

You're missing the cast from string (.val returns string) to numeric:

$(function() {
    $('.submitButton').click(function() {
        $('input').each(function() {
            if ($(this).attr('min')) {
                if (Number($(this).val()) < Number($(this).attr('min'))) {
                    $('#' + $(this).attr('id') + "_errMess").prepend(' Your data should be more than ' + $(this).attr('min'));
                }
            }
        });
    });

score 1 · Answer 3 · edited May 23 '17 at 11:50

1

val() returns string and string "10" IS less than "7" in JavaScript. What you actually need is number comparison, so converting them by parseInt or Number before comparing the strings. You may check the other question on stackoverflow: Why is string "11" less than string "3"? .

By the way, you'd better save the $(this) to a variable instead of calling dollar function repeatedly.

edited May 23 '17 at 11:50

Community

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1

answered Dec 29 '12 at 05:57

Hui Zheng

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a comparison in jquery

3 Answers3