1. Nested For Loops

2. First, the rules to these loops do not change. We are sticking one loop inside another. while(condition) { // loop body } do { // loop body }while(condition); for(integer initialization; condition; iteration) { // loop body }while(condition);

3. while(condition) { while(condition) { // loop body } do { do { // loop body }while(condition); for(integer initialization; condition; iteration) { for(integer initialization; condition; iteration) { // loop body }

4. Example 1 int n = 10; while(n == 10) { while(n > 0) { n--; }

5. Example 2 int n = 10; do { do { n--; }while(n > 0); }while(n == 10);

6. Example 3 for(int k = 0; k < 10; k++) { for(int j = 0; j < 10; j++) { System.out.println(“Hello World”); }

7. Example 3 continued for(int k = 0; k < 10; k++)// scope of variable k is within this entire loop { for(int j = 0; j < 10; j++) // j is only within this loop { System.out.println(“Hello World”); } System.out.println(j); // you cannot do this, j is “dead” }

8. Once a loop begins and encounters another loop, the inner loop now executes until it finishes before the outer loop continues. for(int k = 0; k < 10; k++) { for(int j = 0; j < 10; j++) { System.out.println(“Hello World”); } // Loop in red finishes 10 times before the outer loop can // continue.

9. What’s the output? int j = 0; while(j < 5) { for(int s = 0; s < 5; s++) { System.out.println(“Hello”); } System.out.println(“World”); j++; }

10. What’s the output? int j = 0; do { System.out.println(“World”); for(int s = 0; s < 5; s++) { System.out.println(“Hello”); } j++; }while(j < 10);

11. What’s the output? for(int k = 0; k < 5; k++) { for(int j = 0; j < 5; j++) { System.out.println(“Hello World”); } System.out.println(“Hello World”); }

12. Exercise 1 Print “Hello World” 50 times using two nested for loops. Let outer loop run 10 times and inner loop run 5 times.

13. Exercise 2 Ask for a user input of a number between 1-10. Enter a while loop that will loop exactly the number of times of the input. Inside this while loop, enter a number a for loop that will display “Hello world” 5 times.

14. Exercise 3 Create this Rectangle: 10101010101010101010 It’s a 10 x 5 that prints 10 consistently

15. Exercise 4 Create the triangle 12345678910 123456789 12345678 1234567 123456 12345 1234 123 12 1

16. Exercise 5 Create the Pyramid 1 12 123 1234 12345 123456 Keep going until you reach 10.