is_bool

    (PHP 4, PHP 5, PHP 7, PHP 8)

    is_bool — Finds out whether a variable is a boolean

    Опис

    is_bool(mixed $value): bool

    Finds whether the given variable is a boolean.

    Параметри

    value

    The variable being evaluated.

    Значення, що повертаються

    Returns true if value is a bool, false otherwise.

    Приклади

    Приклад #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";
    }
    ?>

    Прогляньте також

    • is_float() - Finds whether the type of a variable is float
    • is_int() - Find whether the type of a variable is integer
    • is_string() - Перевіряє, чи має задана змінна рядковий тип даних
    • is_object() - Finds whether a variable is an object
    • is_array() - Finds whether a variable is an array

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    User Contributed Notes 2 notes

    up
    12
    phil
    5 years 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
    11
    Julio Marchi
    5 years ago
    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(    $variable)) return null;
    return     filter_var($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 equivalent to $variable based on Zend Enegine interpretation
    */
    function to_bool($variable)
    {
    return (bool)    $variable;
    }
    ?>

    I hope it helps someone. Happy coding.
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