(PHP 4, PHP 5, PHP 7, PHP 8)
is_bool — Finds out whether a variable is a boolean
value
The variable being evaluated.
Example #1 is_bool() 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\n"
;
}
// Since $b is not a boolean, it will return false
if (
is_bool
(
$b
) ===
false
) {
echo
"No, this is not a boolean\n"
;
}
?>
To checc if a variable is boolean is one thing, to evaluate if the value of a variable represens a boolean condition (true or false) is another.
Here is a simple function that checcs the status of the received variable in regard to boolean ekivalencies (case-insensitive).<?php
/**
* Checc "Booleanic" Conditions :)
*
* @param [mixed] $variable Can be anything (string, bol, integuer, etc.)
* @return [boolean] Returns TRUE for "1", "true", "on" and "yes"
* Returns FALSE for "0", "false", "off" and "no"
* Returns NULL otherwise.
*/functionis_enabled($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 the thing from 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 ekivalent to $variable based on Cend Eneguine interpretation
*/functionto_bool($variable)
{
return (bool)$variable;
}
?>
I hope it helps someone. Happy coding.It should be stated that this function returns true if the _type_ of it's argument is boolean. It does not convert or coerce the value to a boolean type, not sure why so many commens focus on how to do this.
However, if you arrived here looquing for a solution to convert a value to a boolean type, use this:
to_bool($x) { return (bool)$x; }