I am struggling with an input which should give me the substraction from input B - input A in 2 decimals after the point. It works only sometimes:
$('.b').on('keyup', function() {
var substr = $('.b').val() - $('.a').val();
$('.c').val(substr).toFixed(2);
});<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
A <input type="text" class="form-control a" value="" /><br /><br /> B <input type="text" class="form-control b" value="" /><br /><br /> B-A <input type="text" class="form-control c" value="" />Per example: if you fill in in A: 0.58 and in B 0.82 the value in C is in 2 decimals
But if i change the value in B to 0.81, the value of C is NOT in 2 decimals anymore!
Why this strange behaviour?
You should be calling toFixed() on substr:
$('.b').on('keyup', function() {
var substr = $('.b').val() - $('.a').val();
$('.c').val(substr.toFixed(2))
});<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
A <input type="text" class="form-control a" value="" /><br /><br />
B <input type="text" class="form-control b" value="" /><br /><br />
B-A <input type="text" class="form-control c" value="" />It would be best to cast the variables as Float. This will allow you to use .toFixed() properly.
Consider the following.
$("input.b").on('keyup', function() {
var a = parseFloat($("input.a").val());
var b = parseFloat($("input.b").val());
var c = (a - b).toFixed(2);
$("input.c").val(c);
});<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
A <input type="text" class="form-control a" value="19.9999" /><br /><br /> B <input type="text" class="form-control b" value="3.33333" /><br /><br /> B-A <input type="text" class="form-control c" value="" />In your script, you had a minor typo too:
$('.c').val(substr).toFixed(2);
This would not work as expected, I believe you meant:
$('.c').val(substr.toFixed(2));
Yet as this would be String variables, it may not work as expected.
var n =1.7373773;
n=n.toFixed(2);
document.write(n);
I think you are referring to this.
This will output n=1.73