Boolean Type

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The boolean type returns the value either TRUE or FALSE

Syntax

In order to specify the boolean variable, use the constants TRUE or FALSE. Both are case-insensitive

<?php

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

?>

Typically, the  control structure depends upon the value of boolean operator. Because, it returns either TRUE or FALSE

<?php

// == is an operator which tests

// equality and returns a boolean

if ($name== "coderz") {

    echo "Coderztoday is the best online tutorial";

}

// this is not necessary...

if ($name ==TRUE) {

    echo "<hr>\n";

}

// ...because this can be used with exactly the same meaning:

if ($name ) {

    echo "<hr>\n";

}

?>

Converting to boolean

To explicitly convert a value to boolean, use the (bool) or (boolean) casts. However, in most cases the cast is unnecessary, since a value will be automatically converted if an operator, function or control structure requires a boolean argument.

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

• the boolean FALSE itself
• the integer 0 (zero)
• the float 0.0 (zero)
• the empty string, and the string "0"
• an array with zero elements
• the special type NULL (including unset variables)

• SimpleXML objects created from empty tags

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

Example

<?php

var_dump((bool) "");        // bool(false)

var_dump((bool) 1);         // bool(true)

var_dump((bool) -2);        // bool(true)

var_dump((bool) "foo");     // bool(true)

var_dump((bool) 2.3e5);     // bool(true)

var_dump((bool) array(12)); // bool(true)

var_dump((bool) array());   // bool(false)

var_dump((bool) "false");   // bool(true)

?>