php man page for is_bool

IS_BOOL(3)								 1								IS_BOOL(3)

is_bool - Finds out whether a variable is a boolean

SYNOPSIS
       bool is_bool (mixed  $var)

DESCRIPTION
	Finds whether the given variable is a boolean.

PARAMETERS
	      o $var
		- The variable being evaluated.

RETURN VALUES
	Returns TRUE if $var is a boolean, FALSE otherwise.

EXAMPLES
       Example #1

	      is_bool(3) examples

	      <?php
	      $a = false;
	      $b = 0;

	      // Since $a is a boolean, it will return true
	      if (is_bool($a) === true) {
		  echo "Yes, this is a boolean";
	      }

	      // Since $b is not a boolean, it will return false
	      if (is_bool($b) === false) {
		  echo "No, this is not a boolean";
	      }
	      ?>

SEE ALSO
       is_float(3), is_int(3), is_string(3), is_object(3), is_array(3).

PHP Documentation Group 														IS_BOOL(3)