Item 45 - Minimize the scope of local variables

From Effective Java 2/e by Joshua Bloch

Advantages

• Increase the readability
• Increate the maintainability
• Reduce the likelihood of error

Technique

• The most powerful technique for minimizing the scope of a local variable is to declare it where it is first used
• Nearly every local variable declaration should contain an initializer

• Loops present a special opportunity to minimize the scope of variables (prefer for loops to while loops)

  // Preferred idiom for iterating over a collection
  for (Element e : c) {
    doSomething(e);
  }
  
  
  // No for-each loop or generics before release 1.5
  for (Iterator i = c.iterator(); i.hasNext(); ) {
    doSomething((Element) i.next());
  }
  

• Keep methods small and focused

Posted by The Finest Artist