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 :
// 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
}
// 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)
// 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
