How to compare two Strings in java program?

Below are 5 ways to compare two Strings in Java:

1. Using user-defined function : Define a function to compare values with following conditions :
   • if (string1 > string2) it returns a positive value.
   • if both the strings are equal lexicographically
     i.e.(string1 == string2) it returns 0.
   • if (string1 < string2) it returns a negative value.
2. Using String.equals()
   • str1.equals(str2);
3. Using String.equalsIgnoreCase()
   • str2.equalsIgnoreCase(str1);
4. Using Objects.equals() : Objects.equals(Object a, Object b)
   • Objects.equals(string1, string2);
5. Using String.compareTo()
   • int str1.compareTo(String str2);