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Difference between equals() and == in Java


Java object has a Memory Location and State (depends on the values in the object).

Integer intObj1 = new Integer(10);

Above we have created an object called "intObj1" and it has a memory location. And also we have assigned value 10 to it,

The “==” operator
Used to compare two Objects. Comparing means checking to see if the two objects are referring to the same memory location.
Example :

String str1 = new String("techoverloads");
// now str2 and str1 reference the same place in memory
String str2 = str1;
if(str1== str2)
   System.out.printlln("str1==str2is TRUE");
else
  System.out.println("str1==str2is FALSE");

Result is,

str1==str2 is TRUEThe equals() method
Used to compare contents of two objects.Checks only the values, not their locations in memory.
Example:

String obj1 = new String("xyz");
String obj2 = new String("xyz");
if(obj1.equals(obj2))
   System.out.printlln("obj1==obj2 is TRUE");
else
  System.out.println("obj1==obj2 is FALSE");

Result is,
obj1==obj2 is TRUE

The "equals()" method is defined in the object class and it's default behavior is as same as the "==" operator. But it is overridden in-order to compare only the contents of the object instead of the location. Java string class overrides the default implementation of "equals()" method and above is an example of that.

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