Java - Comparing two objects ( == instead of .equals)

When we use the == operator, we are actually comparing two object references, to see if they point to the same object. We cannot compare, for example, two strings for equality, using the == operator. We must instead use the .equals method, which is a method inherited by all classes from java.lang.Object.

Here's the correct way to compare two strings.

String abc = "abc"; String def = "def";

// Bad way
if ( (abc + def) == "abcdef" )
{
    ......
}

// Good way
if ( (abc + def).equals("abcdef") )
{
   .....
}