Loop in java
Loop in Java is known as a repetition, it allows the programmer to point out that an action is to be repeated while some condition remain true.
It is implemented in one of three ways:-
1. While loop
2. do/while loop
3. for loop
while loop
The while loop architecture is sufficient to provide any form of repetition. In the while loop, the loop-continuity is tested at the beginning of the loop before the body of the loop is performed. All the things that can be done with the do/while loop and the for loop can be done with the while loop.
Syntax
while(condition)
{
statement(s);
}
Example
public class WhileLoop {
public static void main(String args[]){
int array[]={5,16,95,99,100,180,300};
//array index starts with 0
int x=0;
while(x<7){
System.out.println(array[x]);
x++;
}
}
}
Output
5
16
95
99
100
180
300
do/while loop
The do/while loop tests the loop-continuity condition after the loop body is executed; therefore, the loop body is always executed at least once . When the do/while stop, executing the continues with the statement after the while clause.
Note :- It is not essential to use braces in the do/while loop if there is only one statement in the body .However, the bracket is usually contained to avoid confusion between the while and do/while loop.
Syntax
do
{
statement(s);
} while(condition);
Example
public class DoWhileLoop {
public static void main(String args[]){
int array[]={5,16,95,99,100,180,300};
//array index starts with 0
int i=0;
do{
System.out.println(array[i]);
i++;
}while(i<7);
}
}
Output
5
16
95
99
100
180
300
for loop
The for repetition architecture handles all the details of opposite-controlled repetition.In the for loop the increment expression is executed ,then the loop continuation test is evaluated.
Syntax
for(initialization; condition ; increment/decrement)
{
statement(s);
}
In this initialization is used to initialize (boot up) the loop's control variable, condition is used for the loop -continuation and increment/decrement is used to control variable.
Example
public class ForLoop {
public static void main(String args[]){
for(int x=20; x>10; x--){
System.out.println("The number is: "+x);
}
}
}
Output
The number is: 20
The number is: 19
The number is: 18
The number is: 17
The number is: 16
The number is: 15
The number is: 14
The number is: 13
The number is: 12
The number is: 11