equals( ) vs ==

equals( ) method and the == operator perform two different operations. equals( ) method compares the characters inside a String object. The == operator compares two object references to see whether they refer to the same instance.

The following program shows the differences:


public class Main {
  public static void main(String args[]) {
    String s1 = "java2s.com";
    String s2 = new String(s1);

    System.out.println(s1 + " equals " + s2 + " -> " + s1.equals(s2));
    System.out.println(s1 + " == " + s2 + " -> " + (s1 == s2));
  }
}
  

Here is the output of the preceding example:


java2s.com equals java2s.com -> true
java2s.com == java2s.com -> false
  
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String:
  1. String type and Literals
  2. String Concatenation
  3. String.CASE_INSENSITIVE_ORDER
  4. String Constructor
  5. charAt(int index):Get a single char by index
  6. String: compareTo(String stringValue)
  7. concat(String str)
  8. equals():Compare two string value for equality
  9. equals( ) vs ==
  10. contains(CharSequence s)
  11. copyValueOf(char[] data)
  12. endsWith(String suffix)
  13. format():Format a string
  14. getBytes():Get byte array from string
  15. getChars()
  16. indexOf
  17. intern a string
  18. isEmpty:if string is empty
  19. lastIndexOf()
  20. length() Returns the length of this string
  21. startsWith( )
  22. toLowerCase() and toUpperCase(): convert string case with locale
  23. substring:Get sub string from a string
  24. toCharArray():Get char array from string
  25. toString( )
  26. trim()
  27. valueOf():Convert boolean, char, double, float,int,long,object to String