PHP Tutorial - PHP Boolean

Booleans hold either true or false. Behind the scenes, booleans are integers.

false value

In addition, PHP considers the following values to be false :

• The literal value false


• The integer zero (0)


• The float zero ( 0.0 )


• An empty string ( " " )


• The string zero ( "0" )


• An array with zero elements


• The special type null (including any unset variables)


• A SimpleXML object that is created from an empty XML tag

All other values are considered true in a Boolean context.

We can assign true or false value to a boolean type variable.

<?PHP/* w  w  w .  j  av a2  s  . c o  m*/
    $bool = true;
    print "Bool is set to $booln";
    $bool = false;
    print "Bool is set to $booln";
?>

The code above generates the following result.

Example 2

In the second if statement we compare the integer value to a boolean value.

<?PHP/* w w w  .j a  va  2 s . c o m*/
$a=100;
if($a==100) {
    echo "the variable equals 1!n";
}

if($a==true) {
   echo "the variable is true!";
}
?>

The code above generates the following result.