src/Cli.php
protected function isStrictBoolean($value, &$boolValue = null) {
        if ($value === true || $value === false) {
            $boolValue = $value;
            return true;
        } elseif (in_array($value, ['0', 'false', 'off', 'no'])) {
            $boolValue = false;
            return true;
        } elseif (in_array($value, ['1', 'true', 'on', 'yes'])) {
            $boolValue = true;
            return true;
        } else {
            $boolValue = null;
            return false;
        }
    }
protected function isStrictBoolean($value, &$boolValue = null) {
        if ($value === true || $value === false) {
            $boolValue = $value;
            return true;
        } elseif (in_array($value, ['0', 'false', 'off', 'no'])) {
            $boolValue = false;
            return true;
        } elseif (in_array($value, ['1', 'true', 'on', 'yes'])) {
            $boolValue = true;
            return true;
        } else {
            $boolValue = null;
            return false;
        }
    }
protected function isStrictBoolean ( $ value , & $ boolValue = null ) { if ( $ value === true || $ value === false ) { $ boolValue = $ value ; return true ; } elseif ( in_array ( $ value , [ '0' , 'false' , 'off' , 'no' ] ) ) { $ boolValue = false ; return true ; } elseif ( in_array ( $ value , [ '1' , 'true' , 'on' , 'yes' ] ) ) { $ boolValue = true ; return true ; } else { $ boolValue = null ; return false ; } }
Determine weather or not a value can be represented as a boolean.

This method is sort of like {@link Cli::validateType()} but requires a more strict check of a boolean value.

@param mixed $value The value to test.
@return bool
Determine weather or not a value can be represented as a boolean .