while & do/while & for

Difference between a while loop & do/while loop.

int i = 0;
while(i < 3)
{
System.out.println("Good jobs!");
i++;
}
System.out.println("END");

int i = 0;
do
{
System.out.println("Good jobs!");
i++;
} while(i < 3);
System.out.println("END");

for(int i=0; i<3; i++)
{
System.out.println("Good jobs!");
}
System.out.println("END");

What will be output of the above three program segments?

If the i is inialized to be 5, what will be output of each?

int i = 5;
while(i < 3)
{
System.out.println("Good jobs!");
i++;
}
System.out.println("END");

int i = 5;
do
{
System.out.println("Good jobs!");
i++;
} while(i < 3);
System.out.println("END");

for(int i=5; i<3; i++)
{
System.out.println("Good jobs!");
}
System.out.println("END");

do/while loop will always do at least one time jobs.
while loop may not do the jobs at all.

for(int i=0; i<3; i++)
{
System.out.println("Good jobs!");
}
System.out.println("END");

Steps to run the above "for" loop:

1. initalize i to be 0.
2. check whether i < 3?
3. If the condition is true, do the job - print "Good jobs".
4. Increase i, i++ ( i = 1 now)
5. check whether i < 3?
6. If the condition is true, do the job - print "Good jobs".
7. Increase i, i++ ( i = 2 now)
8. check whether i < 3?
9. If the condition is true, do the job - print "Good jobs".
10. Increase i, i++ (i = 3 now)
11. check whether i < 3?
12. It is false. Therefore jump out the loop. Also, print "END".