int count  = 10;
int inc    = -1;
while ( count  < 100 )   // check the relational operator
{
  System.out.println( "count is:" + count );
  count = count - inc;
}
System.out.println( "Count was " + count + " when it failed the test");

Counting by Tenths

The above program fragment is logically correct, but poorly written because it is harder to understand (and therefore more error-prone) than the following version that does exactly the same thing:

int count  = 10;
int inc    =  1;
while ( count  < 100 )   // check the relational operator
{
  System.out.println( "count is:" + count );
  count = count + inc;
}
System.out.println( "Count was " + count + " when it failed the test");

However, if the values for count and inc came from input data, you might not have much control over what they will be, and it is important to understand what your loop will do.

Here is a program fragment that is to count upward by tenths, that is, 0.0, 0.1, 0.2, 0.3, and so on up to 10.0. These amounts are to be placed in the variable value.

double value ;
int    tenths  = 0;
int    inc     = ____________  // pick an inc value
 
while ( tenths  <= ____________ )   // put in the limit amount
{
  value = ____________  // calculate the current value
  System.out.println( "value:" + value );
  tenths =  tenths + inc ;
}
System.out.println( "done");

This program is an example of a common situation: the actual value you are interested in is not the loop control variable, but a value that is calculated from the loop control variable.