TIOBE - Java Coding Standard

Rule: StringandStringBuffer14

Synopsis:	Use equals() to compare String objects
Language:	Java
Severity Level:	1
Category:	StringandStringBuffer

Description:

Use equals() to compare object references; avoid comparing them with ==. This is because equals() compares object values and == only object references. So if the contents of 2 different string objects is equal (say, both have value "hello"), == returns false.

class Foo {
  boolean bar(String a, String b) {
    return a == b;  // might unexpectedly return false
  }
}