Ternary If

The conditional (ternary) operator is the operator that takes three operands. This operator is frequently used as a shortcut for the if-then-else. However, ternary if can be used in an expression and it can be used to select the value that operated in an expression.

Syntax

<condition> ? <E1> : <E2>

Where condition is a relational expression and E1, E2 are expressions. In the ternary if, when the test condition is true, the expression E1 is executed and E2 is skipped; when the test condition is false, then E1 is bypassed and E2 is executed.

Type Check

For the type checking during the compile time, the value types of the E1 and E2 should be the same.

Example

program exTernaryIf (input, output, error);
import * from io;
var a : integer;
begin
   a := 100;
   writeln(a < 20 ? "a is less than 20" : "value of a is " + string(a))
end.

Output:

value of a is 100