NOT

x	!x
true	false
false	true

The NOT operator in Java is this: ! — exclaimation point. The NOT operator changes true to false and false to true, as seen in the table. This may seem like a silly thing to do, but often it is useful. Sometimes it is more natural to express a condition in a particular way, but the program logic calls for the reverse of what you have written. Time for the NOT operator.

Say that you are shopping for a new computer. You want more than 800 MHz and more than 128 Meg of RAM. Here is s program fragment:

if (  ______(speed > 800 && memory > 128)  )
  System.out.println("Reject this computer");
else
  System.out.println("Acceptable computer");

As it is written, the program is wrong: a computer that exceeds your requirements will be rejected.