Why is my ternary expression not working?

Question

I am trying to set a flag to show or hide a page element, but it always displays even when the expression is false.

$canMerge = ($condition1 && $condition2) ? 'true' : 'false';
...
<?php if ($canMerge) { ?>Stuff<?php } ?>

What's up?

Answer 1

This is broken because 'false' as a string will evaluate to true as a boolean.

However, this is an unneeded ternary expression, because the resulting values are simple true and false. This would be equivalent:

$canMerge = ($condition1 && $condition2);

Answer 2

The value of 'false' is true. You need to remove the quotes:

$canMerge = ($condition1 && $condition2) ? true : false;

Answer 3

Seems to me a reasonable question especially because of the discrepancy in the way PHP works.

For instance, the following code will output 'its false'

$a = '0';

if($a)
{
    echo 'its true';
}
else
{
    echo 'its false';
}

Answer 4

$canMerge = ($condition1 && $condition2);

then

if ($canMerge){
    echo "Stuff";
}