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; }
is_bool
(PHP 4, PHP 5, PHP 7)
is_bool — 변수가 논리형인지 확인
인수
-
var -
평가할 변수.
반환값
var가 boolean이면 TRUE, 아니면
FALSE를 반환합니다.
예제
Example #1 is_bool() 예제
<?php
$a = false;
$b = 0;
// $a는 논리형이기 때문에, true입니다.
if (is_bool($a)) {
echo "논리형입니다.";
}
// $b는 논리형이 아니기 때문에, true가 아닙니다.
if (is_bool($b)) {
echo "논리형입니다.";
}
?>
참고
- is_float() - 변수의 자료형이 소수인지 확인합니다
- is_int() - 변수의 자료형이 정수인지 확인합니다
- is_string() - 변수의 자료형이 문자열인지 확인합니다
- is_object() - 변수가 객체인지 확인합니다
- is_array() - 변수가 배열인지 확인
add a note
User Contributed Notes 3 notes
phil ¶
5 years ago
Julio Marchi ¶
4 years 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)$variable;
}
?>
I hope it helps someone. Happy coding.
Michael Smith ¶
10 years ago
The function in the last comment also converts the string 'false' to a true boolean. Here's a function that does what I think was intended:
<?php
function toBool($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;
}
}
