Loop are use to print the block of code data again by again.In Java Consist of 3 Loops.
1.for loop
2.while loop
3.do while loop
for loop
Public class Loop1{
public static void main(String[] args)
{
for(int x=1; x<10; x++)
{
System.out.println(x);
}
}
}
Output
1
2
3
4
5
6
7
8
9
While loop
Public class Loop1{
public static void main(String[] args)
{
int x=0;
while(x<10)
{
x++;
System.out.println(x);
}
}Output
1
2
3
4
5
6
7
8
9
10
Do while Loop
Public class Loop3
{
public static void main(String[] args)
{
int x=0;
do{
System.out.println(x);
++x;
}
while(x<10);
}
}
Output
0
1
2
3
4
5
6
7
8
9
Exercises
Public class Loop4
{
public static void main(String[] args)
{
int a;
for(a=1; a<10; a++)
{
System.out.println(a*a);
}
}
}Output
1
4
9
16
25
36
49
64
81
Public class Loop5
{
public static void main(String[] args)
{
int x;
for(x=1; x<10; x++)
{
System.out.println((x*x) + 10 + (x*x) );
}
}
}Output
12
18
28
42
60
82
108
138
172
Public class Loop6
{
public static void main(String[] args)
{
int x,y;
for(x=1,y=1; x<10; x++,y++)
{
System.out.println(x+y);
}
}
}Output
2
4
6
8
10
12
14
16
18
Public class Loop7
{
public static void main(String[] args)
{
int x,y,z;
for(x=1,y=1,z=1; x<10; x++,y++,z++)
{
System.out.println(x*y*z);
}
}
}Output
1
8
27
64
125
216
343
512
729
Public class Loop8
{
public static void main(String[] args)
{
int x,y,z;
for(x=1,y=1,z=1; x<10; x++,y--,z--)
{
System.out.println(x*y*z);
}
}
}Output
1
0
3
16
45
96
175
288
Public class Loop9
{
public static void main(String[] args)
{
int x=0;
int y=10;
while(x<10)
{
x++;
System.out.println(x*y);
}
}
}Output
10
20
30
40
50
60
70
80
90
100
Public class Loop9
{
public static void main(String[] args)
{
int x=0;
int y=10;
while(x>-10)
{
x--;
System.out.println(x*y);
}
}
}Output
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
Public class Loop9
{
public static void main(String[] args)
{
int x=1;
int y=2;
int z=3;
while((z=x++)<10)
{
y++;
System.out.println("******");
System.out.println(x*y);
}
}
}Output
******
6
******
12
******
20
******
30
******
42
******
56
******
72
******
90
******
110
Public class Loop9
{
public static void main(String[] args)
{
int x=5;
int y=3;
int z=2;
while(x>1)
{
x--; y--; z--;
System.out.println("x= " +x);
System.out.println("y= " +y);
System.out.println("z= " +z);
}
}
}Output
x= 4
y= 2
z= 1
x= 3
y= 1
z= 0
x= 2
y= 0
z= -1
x= 1
y= -1
z= -2
Public class Loop10
{
public static void main(String[] args)
{
int x=1;
int y =2;
do{
System.out.println((x++)+(y++));
}
while(x<10);
}
}
}Output
3
5
7
9
11
13
15
17
19
Public class Loop10
{
public static void main(String[] args)
{
int x=1;
int y =2;
do{
System.out.println((x++)+(y++));
}
while(x<10);
}
}
}break Keyword
Public class Loop11
{
public static void main(String[] args)
{
for(int x=1; x<10; x++)
{
System.out.println(x);
if(x==5)
{
break;
}
}
}Output
1
2
3
4
5
Public class Loop12
{
public static void main(String[] args)
{
int x=1;
int y=2;
do{
if(x==3)
break;
System.out.println((x++)+(y++));
}while(x<10);
}
}Output
3
5
Public class Loop13
{
public static void main(String[] args)
{
for(int x=1; x<10; x--)
{
System.out.println(x);
if(x==-10)
break;
}
}
}Output
1
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
Continue Keyword
public class Loop14
{
public static void main(String[] args) {
for(int x=1; x<10; x++)
{
if(x==3)
continue;
System.out.println(x);
}
}
}Output
1
2
4
5
6
7
8
9
public class Loop15
{
public static void main(String[] args) {
for(int x=5; x<10; x++)
{
if(x==7)
continue;
System.out.println(x);
}
}
}
Output
5
6
8
9
Example 17
class Example{
public static void main(String args[]){
for(int i = 0 ; i < 3 ; i++)
{
System.out.println("* * * *");
}
}
}
Output
* * * *
* * * *
* * * *
Example 18
class Example{
public static void main(String args[]){
for(int i = 0 ; i < 5 ; i++)
{
for(int j = 0 ; j <= i ; j++){
System.out.print("* ");
}
System.out.println();
}
}
}
Output
*
* *
* * *
* * * *
* * * * *
Find the Maximum Number
import java.util.*;
class Example{
public static void main(String args[]){
Scanner input = new Scanner(System.in);
int number = 0;
int max = 0;
for(int i = 0 ; i < 5 ; i++){
System.out.print("Enter Number " + (i + 1) + " : ");
number = input.nextInt();
if(max < number){
max = number;
}
}
System.out.println();
System.out.println("Maximum Number : " + max);
}
}
Output
Enter Number 1 : 4
Enter Number 2 : 5
Enter Number 3 : 6
Enter Number 4 : 7
Enter Number 5 : 8
Maximum Number : 8