Question

Here is a code:

<span id="dpos">30</span>

<script>
var pxwidth;

$( "#id" )


.bind( "keydown", function( event ) {
 pxwidth = $("#dpos").text();

 if (pxwidth === 0)
 {
 // do something
 }

});

</script>

Here I am trying to get the value of the span element that is used in a conditional (if/else statement). But the statement does not execute. What is the correct usage of if (pxwidth === ?)?

Answer 1

Don’t use === to compare a string with a number.

Instead of:

if (pxwidth === 0)

Use:

if (pxwidth == 0) /* or */ if (pxwidth === "0")

=== only returns true is both values are equal in value and type.
$("#dpos").text() returns a String,
0 is a Number.
Resulting in you comparing them like this: 0 === "0", which is false.

More info on comparison operators here.