Javascript numeric variable comparison not working [duplicate]

Question

I have a form with 2 Submit buttons. One is for Approve the other is for Reject.

The HTML is:

<form action="test.php" method="post" name="sos_submit" id="sos_submit">

  <input type="text" name="qty_indented" value="<?php echo $qty_indented ?>" id="qty_indented" readonly="readonly" />
  <input type="text" name="qty_approved" value="<?php echo $qty_approved ?>" id="qty_approved" />
  <input type="submit" name="da_approve" value="APPROVE" onclick="return submitForm(this)" />
  <input type="submit" name="da_reject" value="REJECT" onclick="return submitForm(this)" />

</form>

And my submitForm(this) Function looks like:

<script>
function submitForm (button){

    if (button.value == "APPROVE"){
        var qty_approved = document.getElementById("qty_approved").value;
        var qty_intended = document.getElementById("qty_indented").value;
        if (qty_approved <= 0){
            alert("Please Enter the Quantity for Approval!");
            submitOK = "false"; 
        }
        else if(qty_approved >= qty_intended){
            alert("Quantity Approved " + qty_approved + " Cannot be more than quantity intended " + qty_intended + " !");
            submitOK = "false";
        }
        if (submitOK == "false") {
            return false;
        }
    }
    else{
        confirm("Are you sure you want to REJECT the Voucher?");    
    }
}
</script>

Although its very simple code, but somehow not working properly.

Even though qty_approved is LESS than qty_indented, the if() statements are executing.

For example, if qty_approved = 5 and qty_indented = 10, then the code should submit the form, but it is NOT. It is showing: Quantity Approved 5 Cannot be more than quantity intended 10 !

Did I do anything wrong?

.value returns a string. qty_approved >= qty_intended performs string comparison. — Felix Kling
– Felix Kling, Commented Jan 15, 2015 at 16:36
They are getting compared as strings -- try to make them int. — Soren
– Soren, Commented Jan 15, 2015 at 16:37

James Thorpe · Accepted Answer · 2015-01-15 16:37:01Z

4

Input boxes are string-based values. You need to convert the values to integers using parseInt:

var qty_approved = parseInt(document.getElementById("qty_approved").value, 10);
var qty_intended = parseInt(document.getElementById("qty_indented").value, 10);

At the moment it's comparing '5' to '10', and alphabetically '5' is greater than '10', which is why it's dropping into that condition.

answered Jan 15, 2015 at 16:37

James Thorpe

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1 Comment

aki2all Over a year ago

That actually solved the issue! I will vote up when it allows me.

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