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Last updated: Sat, 27 Jan 2007

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# is_bool

(PHP 4, PHP 5)

is_bool -- Finds out whether a variable is a boolean

## Описание

bool is_bool ( mixed var )

Finds whether the given variable is a boolean.

## Список параметров

`var`

  The variable being evaluated.

## Возвращаемые значения

Returns `TRUE` if `var` is a boolean, `FALSE` otherwise.

## Примеры

Пример 1. is_bool() examples

`<?php
$a = false;
$b = 0;
// Since $a is a boolean, this is true
if (is_bool($a)) {
echo "Yes, this is a boolean";
}
// Since $b is not a boolean, this is not true
if (is_bool($b)) {
echo "Yes, this is a boolean";
}
?>`

## Смотрите также

is_float()
is_int()
is_string()
is_object()
is_array()

add a note User Contributed Notes
is_bool
21-Apr-2006 04:12
`Small caveat to rh's post: back in PHP 3, "0" would be considered non-empty (i.e., empty would return false), even though (bool) on "0" would also evaluate to false; thus, they would not be complete opposites for someone using PHP 3.`
rh at richardhoward dot net
22-May-2005 11:17
`punkpuke is wrong here; what he means to say is that empty($x) is the opposite of (bool)$x. is_bool($x) returns true where $x === false.`
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is_callable is_array

Last updated: Sat, 27 Jan 2007
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