Looping

Looping:-

To repeat a statement number of times

1.while - entry control

2.for

3.do while – execution control

4.for each

1.Entry control/while

while(condition)

{

}

2.

do

{

}

while(condition);

Note:-

We want to run infinite loop then use

While(true)

{

}

3.For loop

For(initialise;condition,increment)

{

}

Eg.

for(i=1;i<=10;i++)

{

}

System.out.print(“i=”+i);

Result:-

i=11

for(i=10;i>=0;i--)

{

}

System.out.print(“i=”+i);

 Result:-

i=-1

Note:-If we skip the bracket then only one statement will be included in the loop

i.e.

for;

means

for

;

Eg.for(i=10;i>0;i--);

     System.out.print(“i”+i);

Result:-

i=0

Unlabelled Statements:-

While(condition)

{

If(condition)

break;

}

 Then this will break from while loop.

Note:- break will break from inner most loop.

Eg.

for(i=1;i<=10;i++)

{

System.out.print(“i=”+i);

if(i==5)

break;

}

Result:-

12345

Eg.

for(j=1;j<=10;j++)

{

for(i=1;i<=10;i++)

{

System.out.print(“i=”+i);

if(i==j)

break;

}

Result:-

1

12

123

1234

12345

123456

1234567

12345678

123456789

12345678910

Continue:-skip the current iteration

Eg.

for(i=1;i<=10;i++)

{

if(i==5)

continue;

System.out.print(“i=”+i);

}

Result:-

1234678910

Eg.

for(j=1;j<=10;j++)

{

for(i=1;i<=10;i++)

{

if(i=j)

continue;

System.out.print(“i=”+i);

}

}

Result:-

2345678910

1345678910

1245678910

1235678910

1234678910

1234578910

1234568910

1234567910

123456789

Eg.

while(true)

{

for(i=1;i<=10;i++)

{

if(i==5)

break;

System.out.print(“i=”+i);

}

}

Result:-

1234

1234

1234

-----

upto infinity

Labelled Statements:-

eg.

start:

for(j=1;j<=10;j++)

{

for(i=1;i<=10;i++)

{

if(i==j)

break start;

System.out.print(“i=”+i);

}

}

It will break from label i.e start.