Unit 2b

There are three kinds of repetition statements:

• while loop

• for loop

• for-each loop

Loop Control Structure Control Flow

• The condition is checked

• If the condition is true, the loop body is executed

• This repeats as long as the condition is true

• When the condition is false, the loop exits and proceeds to the next statement

The while Statement

while (condition)
    statement;

• If the condition is true, the statement is executed. Then the condition is evaluated again.

How do we change the loop condition?

When using a loop, there is usually a variable associated witht the loop condition

    this is called the loop control variable

There are 3 steaps to creating a loop:

1. Initialize the loop control variable

2. Test the loop control variable

3. Change the loop control variable within the loop body

Example:

A sentinel value indicates the end of the input.

The variable sum maintains a running sum