A Java program to compare two strings lexicographically by creating user defined function. It is embedded at https://coderolls.com/compare-two-strings-lexicographically-in-java

CompareLexicographicallyWithUserDefinedFunction.java

/**
 * The Java program to compare two strings lexicographically
 * by creating user defined function.
 * 
 * @author Gaurav Kukade at coderolls.com
 */

public class CompareLexicographicallyWithUserDefinedFunction {

  public static void main(String[] args) {
    
    String firstString = "Paneer";
    String secondString = "Paneer";
    String thirdString = "Butter";
    String fourthString = "Cheese";
    String fifthString = "PaneerButter";
    
    System.out.println("Comparing two strings lexicographically by user defined function");
    
    System.out.print("\nCompairing firstString ("+firstString+") to the secondString ("+secondString+") returns: ");
    System.out.println(compareString(firstString, secondString));
    
    System.out.print("\nCompairing secondString ("+secondString+") to the thirdString ("+thirdString+") returns: ");
    System.out.println(compareString(secondString, thirdString));
    
    System.out.print("\nCompairing thirdString ("+thirdString+") to the fourthString ("+fourthString+") returns: ");
    System.out.println(compareString(thirdString, fourthString));
    
    System.out.print("\nCompairing fourthString ("+fourthString+") to the firstString ("+firstString+") returns: ");
    System.out.println(compareString(fourthString, firstString));
    
    // Edge case comparing Paneer & PaneerButter
    System.out.print("\nCompairing firstString ("+firstString+") to the fifthString ("+fifthString+") returns: ");
    System.out.println(compareString(firstString, fifthString));
  }
  
  /*
   * User defined function to compare two string lexicographically
   */
  
  public static int compareString(String str, String argumentString) {
    
    int lim= Math.min(str.length(), argumentString.length());
    
    int k=0;
    while(k<lim) {
      if(str.charAt(k)!= argumentString.charAt(k)) {
        return (int) str.charAt(k)- argumentString.charAt(k);
      }
      k++;
    }
    return str.length() - argumentString.length();
  }
}