is_bool

(PHP 4, PHP 5)

is_bool Finds out whether a variable is a boolean

Description

bool is_bool ( mixed $var )

Finds whether the given variable is a boolean.

Parameters

var

The variable being evaluated.

Return Values

Returns TRUE if var is a boolean, FALSE otherwise.

Examples

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";
}

// 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() - Finds whether the type of a variable is float
  • is_int() - Find whether the type of a variable is integer
  • is_string() - Find whether the type of a variable is string
  • is_object() - Finds whether a variable is an object
  • is_array() - Finds whether a variable is an array

Коментарии

Автор:
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; }
2019-01-10 20:21:47
http://php5.kiev.ua/manual/ru/function.is-bool.html
Автор:
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 is a simple function that checks the status of the received variable in regard 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(
$variable)) return null;
    return 
filter_var($variableFILTER_VALIDATE_BOOLEANFILTER_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 equivalent to $variable based on Zend Enegine interpretation
 */
function to_bool($variable

    return (bool)
$variable;
}
?>

I hope it helps someone. Happy coding.
2019-09-08 03:32:25
http://php5.kiev.ua/manual/ru/function.is-bool.html

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