Loop control Definition :
A loop control is defined as the block of statement which is repeatedly executed for a certain number of times. There are three types of loops: While , for and do-while.
Why we use Loop ?
When we need to execute a block of code at several time that time we use looping concept in java .
Advantage of Looping Statement
- To reduce the length of code
- Less memory space
- Time consuming process is reduce, when the programme will execute.
- Reducing burden on the developer
Must Know: Complete Java Topics to be a Professional Programmer
There are three types of Loop Condition :
- For Loop
- While Loop
- do-while loop
For loop :-
The For loop allows to executes a set of instruction untill a certain condition is satisfied. That means, for loop is a statement which allows code to be repeatedly executed. It contains three part Initialization, Condition and Increment or Decrements.
Syntax :
for ( initialization ; condition ; increment/ decrement )
{
Statement 1 ;
Statement 2 ;
}
Flow Diagram
Example of for loop
class Hello { public static void main(String args[]) { int i; for (i=0: i<5; i++) { System.out.println("Hello Friends !"); } } }
Output
Hello Friends ! Hello Friends ! Hello Friends ! Hello Friends ! Hello Friends !
While loop :-
In while loop, the condition may be any expression. the loop statement will be executed till the condition is true .
If the condition is true, the body of the loop is executed, when the condition is false the condition is out of the loop .
Syntax :-
while (condition )
{
Body of the loop
}
Example while loop
class whileDemo { public static void main(String args[]) { int i=0; while(i<5) { System.out.println(+i); i++; }
Output
1 2 3 4 5
Do- While Loop :-
The body of the loop is always executed atleast once. Since the test condition is eveluated at the bottom of the loop.
Syntax :-
do
{
Statement ;
}
While ( Condition )
Example do..while loop
class dowhileDemo { public static void main(String args[]) { int i=20; do { System.out.println("Hello world !"); i++; } while(i<10); } }
Output
Hello world !
Example do..while loop
class dowhileDemo { public static void main(String args[]) { int i=0; do { System.out.println(+i); i++; } while(i<5); } }
Output
1 2 3 4 5