001 /** 002 * Exercise 3.6 from the book. 003 * 004 * @author Kristian Torp, torp (at) cs (dot) aau (dot) dk 005 * @version 1.0 006 */ 007 public class Exercise3_6 { 008 /** 009 * Compares two strings and prints how they successfully compare 010 * 011 * @param s1 012 * The first string 013 * @param s2 014 * The second string 015 */ 016 public static void cmp(String s1, String s2) { 017 // are the two string == 018 if (s1 == s2) { 019 System.out.println(s1 + " == " + s2); 020 } else { 021 System.out.println(s1 + " != " + s2); 022 } 023 024 /* 025 * This does not work if (s1 <= s2) { System.out.println (s1 + " != " + 026 * s2); } 027 */ 028 029 // are the equals 030 if (s1.equals(s2)) { 031 System.out.println(s1 + " equals() " + s2); 032 } else { 033 System.out.println(s1 + " NOT equals() " + s2); 034 035 } 036 037 } 038 039 /** 040 * The main method. 041 */ 042 public static void main(String[] args) { 043 // create two strings and given them default values 044 String str1 = "Viggo"; 045 String str2 = "Hansen"; 046 String str3 = "Hansen"; 047 String str4 = new String("Hansen"); 048 049 // if user arguments then use these 050 if (args.length >= 1) { 051 str1 = args[0]; 052 str2 = args[1]; 053 cmp(str1, str2); 054 055 } else { 056 cmp(str1, str2); 057 cmp(str2, str3); // note this 058 cmp(str2, str4); // note this 059 } 060 } 061 } 062