is_bool

(PHP 4, PHP 5, PHP 7)

is_bool Détermine si une variable est un booléen

Description

is_bool ( mixed $var ) : bool

is_bool() détermine si la variable donnée est un booléen.

Liste de paramètres

var

La variable à évaluer.

Valeurs de retour

Retourne TRUE si var est un booléen, FALSE sinon.

Exemples

Exemple #1 Exemple avec is_bool()

<?php
$a 
false;
$b 0;

// Si $a est un booléen, is_bool retournera true
if (is_bool($a) === true) {
    echo 
"Oui, c'est un booléen.";
}

// Si $b n'est pas un booléen, is_bool retournera false
if (is_bool($b) === false) {
    echo 
"Non, ce n'est pas un booléen.";
}
?>

Voir aussi

  • is_float() - Détermine si une variable est de type nombre décimal
  • is_int() - Détermine si une variable est de type nombre entier
  • is_string() - Détermine si une variable est de type chaîne de caractères
  • is_object() - Détermine si une variable est de type objet
  • is_array() - Détermine si une variable est un tableau

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User Contributed Notes 3 notes

up
7
phil
8 months ago
It should be stated that this function returns true if the _type_ of it's argument is boolean. It does not convert or coerce the value to a boolean type, not sure why so many comments focus on how to do this.
However, if you arrived here looking for a solution to convert a value to a boolean type, use this:

to_bool($x) { return (bool)$x; }
up
1
Julio Marchi
9 days ago
The function Michael Smith published doesn't do the work as it should.

To check if a variable is boolean is one thing, to evaluate if the value of a variable represents a boolean condition (true or false) is another.

Here a simple function that checks the status of the received variable in regards to boolean equivalencies (case insensitive).

<?php
/**
* Check "Booleanic" Conditions :)
*
* @param  [mixed]  $variable  Can be anything (string, bol, integer, etc.)
* @return [boolean]           Returns TRUE  for "1", "true", "on" and "yes"
*                             Returns FALSE for "0", "false", "off" and "no"
*                             Returns NULL otherwise.
*/
function is_enabled($variable)
{
    if (!isset(
$variable)) return null;
    return
filter_var($variable, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE);
}
?>

Of course, it is a simplistic approach, but for the majority of cases it will do the job right.

And, just to put thing in the right perspective, here's a real function that does what Phill disclosed:

<?php
/**
* Convert $variable to boolean (adapted from Phill answer)
*
* @param  [mixed]  $variable  Can be anything
* @return [boolean]           Returns the booelan equivalent to $variable based on Zend Enegine interpretation
*/
function to_bool($variable)
{
    return (bool)
$variable;
}
?>

I hope it helps someone. Happy coding.
up
-4
Michael Smith
5 years ago
The function in the last comment also converts the string 'false' to a true boolean. Here's a function that does what I think was intended:

<?php
function toBool($var) {
  if (!
is_string($var)) return (bool) $var;
  switch (
strtolower($var)) {
    case
'1':
    case
'true':
    case
'on':
    case
'yes':
    case
'y':
      return
true;
    default:
      return
false;
  }
}
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