Unreachable code

Unreachable code is a section of code in a program that can never be executed.

Having unreachable code is bad because it wastes space on the disk, memory, and CPU cache.

Luckily, many modern compilers alert the programmer with a warning or error whenever it detects unreachable code.

Example

<syntaxhighlight lang="java">

 void beepForever() {
     while (true) {
         System.out.println("Beep!");
     }
     System.out.println(":'(");
 }
 </syntaxhighlight>

In this example, ":'(" will never be printed because the loop never exits.