Description:
------------
<?php
$x='E'; // Assignment of Parameter 
if ( $x!='0') // Check if the value is '0' (string)
{
echo "False";
}
else
{
echo "TRUE";
}
?>

Above code returns False while below code returns TRUE for the if condition with a warning message --> Notice: Use of undefined constant E - assumed 'E'

<?php
$x='E'; // Assignment of Parameter 
if ( $x!=0) // Check if the value is 0 (integer)
{
echo "False";
}
else
{
echo "TRUE";
}
?>