PHP Boolean

In this chapter you will learn:

1. What is boolean value in PHP
2. What values are considered false
3. Example - Use PHP boolean value
4. Example - Convert integer to boolean

Description

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.

Example 1

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

<?PHP/* j  a v  a  2s. c  o  m*/
    $bool = true;
    print "Bool is set to $bool\n";
    $bool = false;
    print "Bool is set to $bool\n";
?>

The code above generates the following result.

Example 2

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

<?PHP/* j av  a  2s . co  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.

Next chapter...

What you will learn in the next chapter:

1. What are integers
2. Example - Add two integer together
3. PHP integer literal
4. Example - Integer literal

PHP Data Types

PHP Boolean

PHP Integer

PHP Float

PHP Data Type Cast

PHP Automatic Type Conversion

PHP Super globals

PHP References

PHP Constants