Java Notes

switch Example - Random Insults

The following class could be useful for generating random insults in response to erroneous user input.

Formatting. Some of the cases are formatted on a single line. This is a common style when they do similar short actions. It makes the switch statements much easier to read.

Arrays? This version is written without using arrays, which would provide a better way to do this.

Overloading rand(). The rand() method is overloaded only to demonstrate this feature.

Separate logic from user interface. This program is separated into two files: one file contains the logic for generating the insult in a string. It knows nothing about the user interface, and could equally well be used in a dialog program (as in the test program below), console I/O, a GUI program, or a web-based application.

Random Insult Model

This is the logic of the program, and does no I/O so it would be equally suitable as the logic behind a console program, GUI program, or web server program.

// File   : 1java/textgen/InsultGenerator1.java
// Purpose: Generates random insults.
// Author : Fred Swartz
// License:public domain
// Date   : 2005 May 16
// Comments: The structure of the random generation is 
//           entirely in executable code, which creates a
//           large maintenance problem.
//           A much better way to write this is as a 
//           Data-Driven program, where this information is
//           represented by data structures, and there is a
//           simple program that processes the data.

public class InsultGenerator1 {

    //============================================ badInputInsult
    public static String badInputInsult() {
        String insult = "bad value from badInputInsult???";
        switch (rand(0, 1)) {
            case 0: insult = "What kind of "
                      + infoAdjective() + " "
                      + infoNoun()
                      + " is this, you "
                      + personAdjective() + " "
                      + person()
                      + "?";
                      break;

            case 1: insult = "Never enter this kind of "
                      + infoAdjective() + " "
                      + infoNoun()
                      + " again!!!!";
                      break;
        }
        return insult;
    }

    //==================================================== person
    public static String person() {
        String name = "bad value from person???";
        switch (rand(3)) {
            case 0: name = "idiot"   ; break;
            case 1: name = "imbecile"; break;
            case 2: name = "moron"   ; break;
        }
        return name;
    }

    //=========================================== personAdjective
    public static String personAdjective() {
        String adj = "bad value from infoAdjective???";
        switch (rand(4)) {
            case 0: adj = "clueless"; break;
            case 1: adj = "witless" ; break;
            case 2: adj = "stupid"  ; break;
            case 3: adj = "hopeless"; break;
        }
        return adj;
    }

    //============================================= infoAdjective
    public static String infoAdjective() {
        String adj = "bad value from infoAdjective???";
        switch (rand(5)) {
            case 0: adj = "revolting"  ; break;
            case 1: adj = "insulting"  ; break;
            case 2: adj = "meaningless"; break;
            case 3: adj = "useless"    ; break;
            case 4: adj = "idiotic"    ; break;
        }
        return adj;
    }

    //================================================== infoNoun
    public static String infoNoun() {
        String noun = "bad value from infoNoun???";
        switch (rand(4)) {
            case 0: noun = "nonsense"; break;
            case 1: noun = "crap"    ; break;
            case 2: noun = "swill"   ; break;
            case 3: noun = "garbage" ; break;
        }
        return noun;
    }

    //===================================================== rand
    // Returns random int in range 0...bound-1
    public static int rand(int bound) {
        return rand(0, bound-1);
    }

    //===================================================== rand
    // Returns random int in range low...high
    public static int rand(int low, int high) {
        return low + (int)(Math.random() * (high - low + 1));
    }
}

Console Main program

// File   : 1java/textgen/TestTextGenerator1.java
// Purpose: Show some random insults.
// Author : Fred Swartz
// License:public domain
// Date   : 2005 May 16

import javax.swing.*;

public class TestTextGenerator1 {
    public static void main(String[] args) {
        String display;
        do {
            display = InsultGenerator1.badInputInsult()
                    + "\n\nWould you like another opinion?";
        } while (JOptionPane.showConfirmDialog(null, display) == JOptionPane.YES_OPTION);
    }
}

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