Loading

A for loop is a loop that is used to execute the statement a specific number of times.


Syntax:

for(initialization ; check_condition ; increment/decrement(updation))
{   
  //code to be executed
}

Components:

  • Initialization: It Initializes the value of a variable and is executed only once.
  • Check Condition: Here the condition gets checked, if it returns true then the given code is executed, and if false then it comes out of the loop.
  • Increment/decrement( update ): It updates the value of the initial variable whether it is increment or decrement.

Example:

package quipohouse;
public class  ForLoop {
    public static void main(String[] args) {
       for (int i=1; i<=; i++)
    {
          System.out.println(i);
    }   
}


Output :

1
2
3
4
5

Nested For Loop:

A nested for loop is a for loop inside another for loop. The inner loop executes completely whenever the outer loop executes.

Example:

package quipohouse;
public class NestedForLoop {
	
	public static void main(String[] args) {
	      //outer loop
		for(int i=0;i<n;i++)
        {
             //inner loop
           	for(int j=0;j<=i;j++)
          	{
        	   System.out.print("*");
            }
        	   System.out.println();
         }
   }
}


Output:

 *
 **
 ***
 ****
 *****

For-Each Loop:

For each loop is used on collections classes and arrays.
It does not return the value by its index number rather than the element.

Syntax:

for (data_type identifier:Collection Classs) 
{
        System.out.println(element);    //Prints all the elements
}


Example:

package quipohouse;
class ForEachLoop {
  
  public static void main(String args[]){  
     //declaring an array  
       int arr[]={1,2,3,4,5,6};  
   //traversing the array with for-each loop  
       for(int i:arr)
       {  
          System.out.print(i);  
       }  
    }   
}


Output:

[123456]


Key Point

  • This is easy to use as we don't have to increment the value.
  • It increases the readability of the code but you can't skip any element and can't print in reverse order using this loop rather than other loops.

Which Loop to Use ?

Loop TypeUse Case
For LoopWhen the number of iterations is known
Nested For LoopWhen multiple levels of iteration are needed
For-Each LoopWhen iterating over collections or arrays