The following funciton drove me nuts. How on earth 100x could be equal to 100 and then 100x is reported as an integer?
For the life of me, I cannot figure it out.
You can copy and paste the whole thing and see it for yourself.
I'm missing a simple point somewhere here, help me out guys.
function blp_int($val) {
$orgval = $val;
$num = (int)$val;
echo "<li><font color=red>val: ". $val . " is being checked to see if it's an integer or not";
echo "<li><font color=red>orgval: ". $orgval ;
echo "<li><font color=red>num: ". $num ;
if ($orgval==$num) {
echo "<li><font color=red><b>YES IT IS! the [{$orgval}] is equal to [{$num}]</b>";
return true;
}
return false;
}
if (blp_int("100"))
{
echo "<h1>100 is an integer!</h1>";
}
else
{
echo "<h1>100 is NOT an integer!</h1>";
}
if (blp_int("100x"))
{
echo "<h1>100x is an integer!</h1>";
}
else
{
echo "<h1>100x is NOT an integer!</h1>";
}
the above code, when run returns the following;
val: 100 is being checked to see if it's an integer or not
orgval: 100
num: 100
YES IT IS. the [100] is equal to [100]
100 is an integer!
val: 100x is being checked to see if it's an integer or not
orgval: 100x
num: 100
YES IT IS. the [100x] is equal to [100]
100x is an integer!
I can remedy the situation by adding the following bits
if (!is_numeric($val))
{
return false;
}
to the top of the blp_int function right off the bat but,.. I'm still super curious to find out why on earth php thinks 100x=100 are equals.
As you can see in this example, casting 100x as an integer converts it to 100. Since you are not using strict comparison, '100x' == 100 is true. PHP removes the x from it to make just 100.
You could use strict comparison (which also compares the types), such that '100x' === 100 would return false. Using it, any time a string was compared to an integer, it would return false.
As per your edit: is_numeric may not be the most reliable, as it will return true for numbers formatted as a string, such as '100'. If you want the number to be an integer (and never a string), you could use is_integer instead. I'm not quite sure what exactly you're doing, but i thought I'd add this note.