Controlling Program Flow - JAVA Programming for Engineers - page 94

Thegeneralformoftheforloopinstructionisshownin Figure10-2 .

for keyword
initializing element
test element
update element

for(var = 0; var < 5; var++)
{

// processing statements

}

Figure10-2ElementsoftheforLoopConstruct

Wecanusetheforloopinthefollowingcodefragmentforcalculating
thefactorialaccordingtotheflowchartin Figure10-1 .

int number = 5; // Factorial to be calculated

int facProd, curFactor; // Local variables

// Initialization step
facProd = number; // Initialize operational variable
for (curFactor = number - 1; curFactor > 1; curFactor--)
facProd = curFactor * facProd;
// Done
System.out.println("Factorial is: ", + facProd);

Note that the expression

for(curFactor = number - 1; curFactor > 1; curFactor --)

contains the loop expression and that it includes elements from steps 1, 2,
and 3. The first statement (curFactor = number - 1) sets the initial value of
the loop variable. The second statement (curFactor > 1) contains the test
conditionand determinesiftheloopcontinuesorifitends.Thethirdstate-
ment(curFactor--)diminishestheloopvariableby1duringeachiteration.

Note that while the for loop expression does not end in a semicolon, it
does contain semicolon symbols. In the case of the for loop, the semico-
lon symbol is used to separate the initialization, test, and update elements
of the loop. This action of the semicolon symbol allows the use of multi-
ple statements in each element of the loop expression, as in the following
case:

unsigned int x;
unsigned int y;
for(x = 0,y=5;x<5;x++, y--)
System.out.println("x is:"+x,"yis:"+y);