C++ decision making statements

Decision making structures require that the programmer specify one or more conditions to be evaluated or tested by the program, along with a statement or statements to be executed if the condition is determined to be true, and optionally, other statements to be executed if the condition is determined to be false.

Following is the general form of a typical decision making structure found in most of the programming languages −

C++ decision making

C++ programming language provides following types of decision making statements.

Sr.No Statement & Description
1 if statement

An ‘if’ statement consists of a boolean expression followed by one or more statements.

2 if...else statement

An ‘if’ statement can be followed by an optional ‘else’ statement, which executes when the boolean expression is false.

3 switch statement

A ‘switch’ statement allows a variable to be tested for equality against a list of values.

4 nested if statements

You can use one ‘if’ or ‘else if’ statement inside another ‘if’ or ‘else if’ statement(s).

5 nested switch statements

You can use one ‘switch’ statement inside another ‘switch’ statement(s).

The ? : Operator

We have covered conditional operator “? :” in previous chapter which can be used to replace if...else statements. It has the following general form −

Exp1 ? Exp2 : Exp3;

Exp1, Exp2, and Exp3 are expressions. Notice the use and placement of the colon.

The value of a ‘?’ expression is determined like this: Exp1 is evaluated. If it is true, then Exp2 is evaluated and becomes the value of the entire ‘?’ expression. If Exp1 is false, then Exp3 is evaluated and its value becomes the value of the expression.