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The statements in the for loop repeat continuously for
a specific number of times.
The while and do-while
loops repeat until a certain condition is met. The for loop
repeats until a specific count is met. Use a for loop when the
number of repetitions is known, or can be supplied by the user. The
coding format is:
for(startExpression; testExpression;
countExpression)
{
block of code;
}
The startExpression is
evaluated before the loop begins. It is acceptable to
declare and assign in the startExpression
(such as int x = 1;). Java evaluates the startExpression
only once, at the beginning of the loop.
CAUTION: When
the following code is written:
for (int x= 1; x<=10; x++)
{
some
code here;
}
x will not be recognized as a
variable for future use in the program outside of the loop. If x
is to be used beyond the scope of the loop, be sure to declare x prior
to entering the loop.
The countExpression
executes after each trip through the loop. The count may
increase/decrease by an increment of 1 or of some other value. The testExpression
evaluates to TRUE or FALSE.
While TRUE, the body of the loop repeats. When the
testExpression becomes FALSE,
Java stops looping and the program continues with the statement immediately
following the
for loop in the body of the program.
Braces are not
required if the body of the for loop consists of only ONE
statement. Please indent the body of
the loop for readability.
Be aware that when a for
loop terminates, the value stored in the computer's memory under the looping
variable will be "beyond" the testExpression in the loop. It must be sufficiently large (or small)
to cause a false condition.
for(x = 0; x <= 15; x++)
System.out.println("Patty"); |
When this loop is finished,
the value 16 is stored in x. |
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