Short circuit evaluation is the semantics of some Boolean operators in some programming languages in which the second argument is executed or only evaluated if the first argument is not sufficient to determine the value of the expression: when the first argument of the AND function evaluate to false, the global value must be false; and when the first argument of the OR function evaluates to true, the global value must be true. In some programming languages (Lisp, Perl, Haskell, due to lazy evaluation), the usual Boolean operators are short-circuited. In others (Ada, Java), both short-circuit and standard Boolean operators are available. For some Boolean operations, such as exclusive or (XOR), a short circuit is not possible, because both operands are always necessary to determine the result.
