ULTIMATE PHP TUTORIAL!!!!

[legokiller666]

Get http://www.php.net/manual/en/manual.zip IT COVERS EVERYTHING!!!!!

[liljim]

At 7/21/01 06:27 PM, legokiller666 wrote: Get http://www.php.net/manual/en/manual.zip IT COVERS EVERYTHING!!!!!

Finally... the penny drops :P

[legokiller666]

now.... umm

Booleans
This is the easiest type. A boolean expresses a truth value. It can be either TRUE or FALSE.

Note: The boolean-type was introduced in PHP 4.

Syntax
To specify a boolean-literal, use either the keyword TRUE or FALSE. Both are case-insensitive.

$foo = True; // assign the value TRUE to $foo

Usually you use some kind of operator which returns a boolean value, and then pass it on to a control structure.

if ($action == "show_version") // == is an operator which returns a boolean
{
echo "The version is 1.23";
}

// this is not necessary:
if ($show_separators == true)
{
echo "<hr>
";
}

// because you can simply type this:
if ($show_separators)
{
echo "<hr>
";
}

Converting to boolean
To explicitly convert a value to boolean, use either the (bool) or the (boolean) cast. However, in most cases you do not need to use the cast, since a value will be automatically converted if an operator, function or control structure requires a boolean argument.

See also Type Juggling.

When converting to boolean, the following values are considered FALSE:

the boolean FALSE

the integer 0 (zero)

the double 0.0 (zero)

the empty string, and the string "0"

an array with zero elements

an object with zero elements

the special value NULL

Every other value is considered TRUE (including any resource).

Warning
-1 is considered TRUE, like any other non-zero (whether negative or positive) number!