1. What output is produced by the following fragment?
int num = 1, max = 20;
while (num < max) {
if (num%2 == 0)
System.out.println(num);
num++ }

2. Objectives
To define and illustrate the correct syntax for the For Statement
To apply the For Statement in your code as part of the algorithm
Correctly analyze when to use the While Loop vs. the For Loop

3. The for Statement The for statement has the following syntax:
The initialization
is executed once
before the loop begins
The statement is
executed until the
condition becomes false
Reserved
word
for ( initialization ; condition ; increment )
statement;
The increment portion is executed at the end of each iteration
The condition-statement-increment cycle is executed repeatedly

4. The for Statement
A for loop is functionally equivalent to the following while loop structure:
initialization;
while ( condition ) {
statement;
increment; }

5. Logic of a for loop initialization condition evaluated false statement
true
increment

6. The for Statement
Like a while loop, the condition of a for statement is tested prior to executing the loop body
Therefore, the body of a for loop will execute zero or more times
It is well suited for executing a loop a specific number of times that can be determined in advance
See Counter2.java (page 161)
See Multiples.java (page 163)
See Stars.java (page 165)

7. The for Statement
Each expression in the header of a for loop is optional
If the initialization is left out, no initialization is performed
If the condition is left out, it is always considered to be true, and therefore creates an infinite loop
If the increment is left out, no increment operation is performed
Both semi-colons are always required in the for loop header

8. Choosing a Loop Structure
When you can’t determine how many times you want to execute the loop body, use a while statement
If you can determine how many times you want to execute the loop body, use a for statement

9. While Loop For Loop
int num = 1, max = 20; for (int num = 1; num < 20; num++) while (num < max) { { if (num%2 == 0) if (num%2 == 0) System.out.println(num); System.out.println(num); } num++ }