A nested loop is a loop within a loop, an inner loop within the body of an outer one.
Working:
- The first pass of the outer loop triggers the inner loop, which executes to completion.
- Then the second pass of the outer loop triggers the inner loop again.
- This repeats until the outer loop finishes.
- A break within either the inner or outer loop would interrupt this process.
The Function of Nested loop :
Java
// Nested for loop import java.io.*;class GFG { public static void main(String[] args) { for (int i = 0; i < 3; i++) { for (int j = 0; j < 3; j++) { System.out.print("GFG! "); } System.out.println(); } }} |
Output
GFG! GFG! GFG! GFG! GFG! GFG! GFG! GFG! GFG!
Label the loops:
This is how we can label the name to the loop:
labelname :for(initialization;condition;incr/decr){
//code to be executed
}
Java
// Naming the loop import java.io.*; class GFG { public static void main(String[] args) { // Type the name outside the loop outer: for (int i = 0; i < 5; i++) { System.out.println("GFG!"); } }} |
Output
GFG! GFG! GFG! GFG! GFG!
Rules to Label the loops:
- Label of the loop must be unique to avoid confusion.
- In the break statements use labels that are in scope. (Below is an implementation)
Java
// Break statements and naming the loops import java.lang.*; public class GFG { public static void main(String[] args) { // Using Label for outer and for loop outer: for (int i = 1; i <= 3; i++) { // Using Label for inner and for loop inner: for (int j = 1; j <= 3; j++) { if (j == 2) { break inner; } System.out.println(i + " " + j); } if (i == 2) { break outer; } } }} |
Output
1 1 2 1
