if

(if EXPRESSION EXPRESSION EXPRESSION)
The first expression (known as the "test" expression) is evaluated. If the expression evaluates to true, the result of the if expression is the result of evaluating the second expression (often called the "then" clause). If the expression evaluates to false, the result of the if expression is the result of evaluating the third expression (known as the "else" clause). If the result of evaluating the test expression is neither true nor false, it is an error.

Beginning Student Language