1. Chapter 9
Repetition

2. Objectives Code programs using the following looping techniques:
While Loop
Do While Loop
For Loop
Explain when the Break and Continue statements would be used when coding loops.
Walk through While, Do While, and For loops documenting variables as they change.

3. while loop While Syntax: Flowchart:
while (boolean condition) {         repeated statements   }

4. while loop example: While : Output:
int counter = 1;  while (counter <=5)  {        System.out.println ("Hello " + counter);        counter ++; }
Hello 1 Hello 2 Hello 3 Hello 4 Hello 5

5. do while loop Do While Syntax: Flowchart:
do {          repeated statements   } while (boolean condition);

6. do while loop example: Do While : Output:
Hello 1 Hello 2 Hello 3 Hello 4 Hello 5
int counter = 1; 
do {
System.out.println("Hello " + counter); 
counter++; 
}  while (counter <=5);

7. for loop Initialization - initializes the start of the loop.
for (initialization;   test;    increment)  {            statements; }
Initialization - initializes the start of the loop.
Example: int i = 0;
Boolean Test - occurs before each pass of the loop.
Example: i<10;
Increment - any expression which is updated at the end of each trip through the loop.
Example: i ++,   j+=3
Statements are executed each time the loop is executed.

8. for loop logic

9. for loop example 1: for loop Results
for (int counter =1;  counter <=5;  counter++ ) {
System.out.println ("Hello  " + counter); }
Hello 1 Hello 2 Hello 3 Hello 4 Hello 5

10. for loop example 2: for loop with modulus results
for (int number = 0;   number <1000;   number++) {           if ( number  %  12  = =  0 )  {                    System.out.println("Number is " + number); 
} }
..... etc. Number is 996

11. for loop example 3: for loop to print even numbers from 1 to 20
results
for (int number = 2;   number <=20;   number+=2) {       
  System.out.println("Number is " + number);  }
The number is 2 The number is 4 The number is 6 The number is 8
The number is 10
The number is 12
The number is 14
The number is 16
The number is 18
The number is 20

12. for loop example 4: for loop with multiple initialization & increments
results
  for (int i=0,  j=0 ;  i*j < 1000;  i++,  j+=2) {
      System.out.println( "The answer is " + i + " * " + j
+ " = " + i*j );  }

13. Break Statement for (int index =1; index<= 1000; index ++) {
if (index   ==   400) {
break;
}   System.out.println("The index is " + index);  }

14. Continue Statement for (int index = 1, index <= 1000; index ++) {
if (index == 400)  {
continue; 
} System.out.println("The index is " + index);  }