BooleansPodręcznik PHPPoprzedniRozdział 6. TypesNastępnyBooleans This is the easiest type. A boolean expresses a truth value. It can be either TRUE or FALSE. Notatka: The boolean type was introduced in PHP 4. Syntax To specify a boolean literal, use either the keyword TRUE or FALSE. Both are case-insensitive. $foo = True; // assign the value TRUE to $foo Usually you use some kind of operator which returns a boolean value, and then pass it on to a control structure. if ($action == "show_version") { // == is an <link linkend="language.operators">operator</link> which returns a <type>boolean</type> echo "The version is 1.23"; } // this is not necessary: if ($show_separators == true) { echo "<hr>\n"; } // because you can simply type this: if ($show_separators) { echo "<hr>\n"; } Converting to boolean To explicitly convert a value to boolean, use either the (bool) or the (boolean) cast. However, in most cases you do not need to use the cast, since a value will be automatically converted if an operator, function or control structure requires a boolean argument. See also Type Juggling. When converting to boolean, the following values are considered FALSE: the boolean FALSEthe integer 0 (zero) the float 0.0 (zero) the empty string, and the string "0"an array with zero elementsan object with zero elementsthe special type NULL (including unset variables) Every other value is considered TRUE (including any resource). Ostrzeżenie -1 is considered TRUE, like any other non-zero (whether negative or positive) number! PoprzedniSpis treściNastępnyTypesPoczątek rozdziałuIntegers