Nested Loops: Loops within loops

Predict the output:

1. for (int i = 1; i <= 3; i ++)

{

for (int j = 1; j <=2; j++)

{

System.out.println (i + + j);

}

}

2. Which loop executes more times, the inner or the outer?

3. Predict the output:

int x = 5;

for (int j = 1; j <= x; j++)

{

System.out.println (j);

x = 10;

}

4. Write a nested for loop for the following sequence:

What pattern do you see?

How many loops are there?

Which is the inner? Which is the outer?

1123212331234123

5. Write a nested for loop for the following sequence:

111234121234211234221234311234321234

6. Trace and predict the output for:

for (int i = 0; i <= 10; i = i + 2)

{ System.out.println (i*i); }

7. Trace and predict the value of j at the end of the loop:

int j = 10;

for (int i = 10; i >= 0; i--)

{

j--;

}

8. Trace and predict the value of n at the end of the loop:

int n = 0;

for (int i = 1; i <= 5; i++)

{

for (int j = 0; j < i; j++)

{ n = n + j;

}

}

9. Program: Write a for loop that will take a value from the user and print out the even numbers from 2 to the entered value.

10. Program: Write a for loop that will take a value from the user and print out the multiples of 5 from 5 to the number.