The For Statement

The 'for' loop is more compact than the 'while' and 'do' loops and automatically updates the loop counter at the end of each iteration. Both 'for' and 'while' loops are designed for different situations. You'll learn more about when to use each later.

11. Omitting Parts of the for


No. In more complicated expressions using a postfix operator instead of a prefix operator usually
makes a difference, but not here.

Omitting Parts of the for

for loop
while loop
for ( initialize ; test ; change )
  loopBody ;
while ( test )

Parts of a for can be omitted. Since the three parts of a for are the three parts of any loop, when a part is eliminated from a for it has to be done elsewhere. Recall that the  for is equivalent to a while.

You can omit the initialize part from the for loop. It now acts the same as a while loop with its initialize part omitted. Doing this is useful when initialization is complicated and you wish to do it in several statements before the loop. For example, initialization may depend on user input:

// get initial value of count from the user here
    for (    ; count < 13; count++  )  
      System.out.println( "count is: " + count ); 
    System.out.println( "\nDone with the loop.\nCount is now" + count);

Enter initial value:   


Question 11:

Do you think that the change part of a for can be omitted (as long as it is done somewhere else)?