From Beginner to Expert: Java Loop Programming

 Loops :

•   Loops are used to execute a set of statements repeatedly until a particular condition is satisfied.

Types of Loops :

  for loop: This executes a statement a particular number of times.

  while loop: This executes a statement an unknown number of times.

  do-while loop: This executes a statement at least one time.

The syntax for the "for" loop is :

  for(Variable Initialization; Boolean_Expression Test; Increment/Decrement){

   //Statements

}

Example :

package selenium;

public class Java_practise {

public static void main(String[] args) {

  // This will print -- 0,1,2,3,4,5

for(int Increment = 0;Increment<=5;Increment++){

System.out.println("Count is  ==> " + Increment );

}

// This will print -- 5,4,3,2,1,0

for(int Decrement = 5;Decrement>=0;Decrement--){

System.out.println("Count is ==> " + Decrement );

}

// This will print -- 0,2,4

for(int Increment = 0;Increment<=5;Increment+=2){

System.out.println("Skip every one another  ==> " + Increment );

}

// This will print -- 0,1,2,3,4,5

for(int Count = 0;Count<=10;Count++)

{

if(Count==6){

break;

}

System.out.println("Count is ==> " + Count );

}

// This will just print -- 3

            for(int Count = 0;Count<=5;Count++){

             if(Count==3){

         System.out.println("Count is ==> " + Count);

          continue;

}

}

}

}

The syntax for the while loop :

   while(Boolean_Expression Test){

//Statements

}

Example :

package selenium;

public class Java_practise {

   public static void main(String[] args) {

int Count = 0;

// This will print -- 5,10,15,20,25

while(Count < 25){

Count = Count + 5;

System.out.println("Count is ==> "+ Count);

}        

}

}

The syntax for the do-while loop  :

   do{

//Statements

}while(Boolean_Expression Test);

Example :

package selenium;

public class Java_practise {

  public static void main(String[] args) {

int CountOnce = 25;

System.out.println("<==== Next Count ====>");

// This will just print once 

do{

CountOnce = CountOnce + 5;  

System.out.println("Count is ==> "+ CountOnce);

}while(CountOnce < 25);

     

}

}

The syntax for enhanced for loop :

   for (data_type variable: array_name)

Examples :

package selenium;

public class Java_practise {

     public static void main(String[] args) {

// Array of String storing days of the week

    String days[] = { "Mon", "Tue", "Wed", "Thr", "Fri", "Sat", "Sun"};

    // Enhanced for loop, this will automatically iterate on the array list 

    for (String dayName : days) {

      System.out.println("Days ==> "+ dayName);

    }

    System.out.println("<==== Normal For Loop ====>");

    // Normal for loop

    for (int i=0; i < days.length; i++) {

        System.out.println("Days ==> "+ days[i]);

     }

}

}