Decision making structures requires the programmer to 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.
Statement |
Description |
if statement |
An if statement consists of a boolean expression followed by one or more statements. |
if...else statement |
An if statement can be followed by an optional else statement, which executes when the boolean expression is false. |
nested if statements |
You can use one if or else if statement inside another if or else if statement(s). |
switch statement |
A switch statement allows a variable to be tested for equality against a list of values. |
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;
Where Exp1, Exp2, and Exp3 are expressions. Notice the use and placement of the colon.
The value of a ? expression is determined as follows: 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.