Comparing strings in java

Question

String string1 = \"Hi there\";
String string2 = \"Hi\";
String string3 = \"Hi\";

System.out.println(string1.substring(0, string2.length()) == string2); //1
System.o         


        

Answer 1

Java provides two basic mechanisms for testing for equality. The “==” operator can be used to test primitive values for equality, and can also be used to determine if two object references point to the same underlying object. For Java objects, the equals(Object) method will return true if the argument is equal to the object on which the method is invoked, where equality is defined by the object’s class semantics.

Since Strings are objects, the equals(Object) method will return true if two Strings have the same contents, i.e., the same characters in the same order. The == operator will only be true if two String references point to the same underlying String object. Hence two Strings representing the same content will be equal when tested by the equals(Object) method, but will only by equal when tested with the == operator if they are actually the same object.

Quoted from JavaTechniques:http://javatechniques.com/public/java/docs/basics/string-equality.html