Thread: Problems with incrementing/decrementing in a for loop..

Hello. I cant figure this out. This is what i am getting.

Displaying my name substracting one character.
1[ Hector & Jorge % Farinas ]
1[ ector & Jorge % Farinas ]
1[ ctor & Jorge % Farinas ]
1[ tor & Jorge % Farinas ]
1[ or & Jorge % Farinas ]
1[ r & Jorge % Farinas ]
1[ & Jorge % Farinas ]
1[ & Jorge % Farinas ]
1[ Jorge % Farinas ]
1[ Jorge % Farinas ]
1[ orge % Farinas ]
1[ rge % Farinas ]
1[ ge % Farinas ]
1[ e % Farinas ]
1[ % Farinas ]
1[ % Farinas ]
1[ Farinas ]
1[ Farinas ]
1[ arinas ]
1[ rinas ]
1[ inas ]
1[ nas ]
1[ as ]
1[ s ]
1[ ]

On the left i want starting from the length of the array all the way down to 0. (ex: 24 - 0 in this case). And also I want the name instead of removing the characters from beginning to end, i want it from end to beginning. Here is my code..

public static void DisplayName(String MyNameDisplay[])
            {
             System.out.println("\nDisplaying my name substracting one character.");
             for(int seccounter = MyNameDisplay.length; seccounter > 0; seccounter--)
             for (String name : MyNameDisplay)
             for(int counter = 0; counter < name.length()+1; counter++)
             System.out.println(seccounter + "[ " + name.substring(counter, name.length())+ " ]");
 
 
            }

Thank you in advance.

Your name is a single String, so why are you passing an array of Strings to your method?

Anyhow, You're looping through that array (which presumably only contains a single String - your name), then processing each String. To display the name length, you should use 'counter' which counts each reduction in name length. To make this value count down instead of up in the display, use name.length() - counter.

The outer loop appears to have no useful function at all...

I think the OPs problem is the lack of a design. No time was spent with paper and pencil to figure out how to work thru the process with pointers/indexes and substrings to get his desired output.
Without thought through logic, writing code is a waste of time.

Originally Posted by Norm

I think the OPs problem is the lack of a design. No time was spent with paper and pencil to figure out how to work thru the process with pointers/indexes and substrings to get his desired output.

I agree.

Without thought through logic, writing code is a waste of time.

Quite - that's the most important guideline, and the one most often ignored by novices. Writing the code should be just translating a detailed design into Java. Designing an application requires careful thought, and writing code requires total attention, so it's not possible to make a good job of doing both at once, especially for novices for whom both skills are rudimentary.

Thank you guys for all the input. Actually this is my second program in Java, the professor never mentioned anything about pencil and paper. For just being my second program I think I did pretty good with the help of your comments, other forums and Google. Yes I have much to learn. Anyways, the only thing I need is the problem in the first post and try to make the code better, I have the right output but I know I can make the code better like in the Method "NameFindChar". I know there is a better way of doing it, instead of declaring all those variables I can do like an Array and loop through it, i just don't know how to implement it yet. Anyways the only part I need is this :

Using a for loop, display to the screen, the string containing your name so that each
loop will NOT contain the last character on the previous line,
with the length of the string being printed, and the string surrounded by square brackes []

NOTE: Every method dealing with your name, MUST be called from main, PASSING your name to it.

i.e: 32 [George $ Washington % Rodriguez ]
31 [George $ Washington % Rodriguez]
30 [George $ Washington % Rodrigue]
29 [George $ Washington % Rodrigu]
28 [George $ Washington % Rodrig]
27 [George $ Washington % Rodri]
26 [George $ Washington % Rodr]
25 [George $ Washington % Rod]
24 [George $ Washington % Ro]
23 [George $ Washington % R]
22 [George $ Washington % ]
21 [George $ Washington %]
20 [George $ Washington ]
19 [George $ Washington]
18 [George $ Washingto]
17 [George $ Washingt]
16 [George $ Washing]
15 [George $ Washin]
14 [George $ Washi]
13 [George $ Wash]
12 [George $ Was]
11 [George $ Wa]
10 [George $ W]
9 [George $ ]
8 [George $]
7 [George ]
6 [George]
5 [Georg]
4 [Geor]
3 [Geo]
2 [Ge]
1 [G]

And this is the output I am getting :

0[ Hector & Jorge % Farinas ]
0[ Hector & Jorge % Farina ]
0[ Hector & Jorge % Farin ]
0[ Hector & Jorge % Fari ]
0[ Hector & Jorge % Far ]
0[ Hector & Jorge % Fa ]
0[ Hector & Jorge % F ]
0[ Hector & Jorge % ]
0[ Hector & Jorge % ]
0[ Hector & Jorge ]
0[ Hector & Jorge ]
0[ Hector & Jorg ]
0[ Hector & Jor ]
0[ Hector & Jo ]
0[ Hector & J ]
0[ Hector & ]
0[ Hector & ]
0[ Hector ]
0[ Hector ]
0[ Hecto ]
0[ Hect ]
0[ Hec ]
0[ He ]
0[ H ]

I know that my loop is wrong.. Here is the code

public static void DisplayName(String MyNameDisplay[]) //Method for displaying my name with one character less in the nextline.
            {
             System.out.println("\nDisplaying my name substracting one character.");
 
             int scounter = MyNameDisplay.length;
	     while(scounter > 0)
	       {
	          scounter--;
	       }
             for (String name : MyNameDisplay)
             for(int counter = 0; counter < name.length(); counter++)
 
             System.out.println(scounter + "[ " + name.substring(0, name.length()-counter)+ " ]");
 
 
            }

And here is the whole Homework so you guys can see the "NameFindChar" method.

/*
Author : Hector Farinas
Course : COP 2250 M-W 11:00 AM
Professor : Michael Robinson
Program # : This program implement methods, if, else if, else, while, for, print, println, printf, Scanner,
 primitive types, String class with several methods, single dimension array, modulus,error trapping.
Due Date : 06/13/2011
Certification:
I hereby certify that this work is my own and none of it is the work of any other person.
..........{ Hector Farinas }..........
*********************************************************************/
 
package hectorfarinasassignment2;
import java.util.Scanner;
 
 
 
/**
 *
 * @author Kl2eativ
 */
public class Main {
 
 
  public static void main(String[] args)
    {
      //Calling methods related to number operations
          DivideNums();
          DisplayNumsMod();
 
 
    //Single Dimension array
     String ArrayMyName[] = {"Hector & Jorge % Farinas"};
 
    //Calling all methods related to ArrayName
     NameFindChar(ArrayMyName);
     DisplayName(ArrayMyName);
     PrintAllUpper(ArrayMyName);
     PrintAllLower(ArrayMyName);
     PrintNoSpaces(ArrayMyName);
     UpperVtoLowerC(ArrayMyName);
     UpperCtoLowerV(ArrayMyName);
     PrintNameBackwards(ArrayMyName);
     PrintNameAscii(ArrayMyName);
 
   }
 
      public static void DivideNums() //Method for performing the division between two numbers
      {
      int fnum=0, secnum; //Variables for the user input
 
      Scanner myScanner = new Scanner(System.in);
      System.out.println ("Enter two numbers and I will divide them. Press 999 to quit.");
 
            while(fnum != 999)
              {
                System.out.print("Please enter first number: ");
                fnum = myScanner.nextInt();
                if (fnum == 999)
                {
                 System.out.println("You quit.");
                 break;
                }
                System.out.print("Enter second number: ");
                secnum = myScanner.nextInt();
 
                if(secnum == 999)
                 {
                 System.out.println("\nYou quit.");
                 break;
                 }
 
                else if (secnum == 0)
                {
                    System.out.print("Division cannot be by 0. Enter any number other than 0: ");
                    secnum = myScanner.nextInt();
 
                    System.out.format("The answer is = %.2f%n", (float)fnum / secnum);
                }
 
               else
 
                   System.out.format("The answer is = %.2f%n", (float)fnum / secnum);
 
            }
      }
 
 //****************************************************************************************************************
    public static void DisplayNumsMod() //Method for displaying all number from 0-1000 where mod 5 is 3.
    {
       System.out.println("\nThese are all numbers from 0 - 1000 where mod5 = 3.");
       for(int i=0; i <= 1000; i++)
        {
          if(i%5 == 3)
           System.out.println(i);
        }
 
    }
 //*****************************************************************************************************************
    public static void NameFindChar(String MyNameDisplay[]) //Method for displaying position and what each character is.
    {
        //Variables for the conditions of the ifs
        char vowela = 'a';
        char vowele = 'e';
        char voweli = 'i';
        char vowelo = 'o';
        char consonantc = 'c';
        char consonantf = 'F';
        char consonantg = 'g';
        char consonanth = 'H';
        char consonantj = 'J';
        char consonantn = 'n';
        char consonantr = 'r';
        char consonants = 's';
        char consonantt = 't';
        char symbol = '&';
        char symbol1 = '%';
        char space = ' ';
 
 
        for(String name : MyNameDisplay)
        System.out.println("\nMy name is : " + name);
        for(String name : MyNameDisplay)
        for(int counter = 0; counter < name.length(); counter++ )
          {
            if(name.charAt(counter)== vowela)
            System.out.println("Character [" + name.valueOf(vowela) + "] at position " + counter + " is a vowel.");
            else if(name.charAt(counter)== vowele)
            System.out.println("Character [" + name.valueOf(vowele) + "] at position " + counter + " is a vowel.");
            else if (name.charAt(counter)== voweli)
            System.out.println("Character [" + name.valueOf(voweli) + "] at position " + counter + " is a vowel.");
            else if(name.charAt(counter)== vowelo)
            System.out.println("Character [" + name.valueOf(vowelo) + "] at position " + counter + " is a vowel.");
            else if(name.charAt(counter)== consonantc)
            System.out.println("Character [" + name.valueOf(consonantc) + "] at position " + counter + " is a consonant.");
            else if(name.charAt(counter)== consonantf)
            System.out.println("Character [" + name.valueOf(consonantf) + "] at position " + counter + " is a consonant.");
            else if(name.charAt(counter)== consonantg)
            System.out.println("Character [" + name.valueOf(consonantg) + "] at position " + counter + " is a consonant.");
            else if(name.charAt(counter)== consonanth)
            System.out.println("Character [" + name.valueOf(consonanth) + "] at position " + counter + " is a consonant.");
            else if(name.charAt(counter)== consonantj)
            System.out.println("Character [" + name.valueOf(consonantj) + "] at position " + counter + " is a consonant.");
            else if(name.charAt(counter)== consonantn)
            System.out.println("Character [" + name.valueOf(consonantn) + "] at position " + counter + " is a consonant.");
            else if(name.charAt(counter)== consonantr)
            System.out.println("Character [" + name.valueOf(consonantr) + "] at position " + counter + " is a consonant.");
            else if(name.charAt(counter)== consonants)
            System.out.println("Character [" + name.valueOf(consonants) + "] at position " + counter + " is a consonant.");
            else if(name.charAt(counter)== consonantt)
            System.out.println("Character [" + name.valueOf(consonantt) + "] at position " + counter + " is a consonant.");
            else if(name.charAt(counter)== symbol)
            System.out.println("Character [" + name.valueOf(symbol) + "] at position " + counter + " is not a vowel, or a consonant, or a space.");
            else if(name.charAt(counter)== symbol1)
            System.out.println("Character [" + name.valueOf(symbol1) + "] at position " + counter + " is not a vowel, or a consonant, or a space.");
            else if(name.charAt(counter)== space)
            System.out.println("Character [" + name.valueOf(space) + "] at position " + counter + " is a space.");
          }
      }
 
 
 
 
 
 //*******************************************************************************************************************
            public static void DisplayName(String MyNameDisplay[]) //Method for displaying my name with one character less in the nextline.
            {
             System.out.println("\nDisplaying my name substracting one character.");
 
             int scounter = MyNameDisplay.length;
	     while(scounter > 0)
	       {
	          scounter--;
	       }
             for (String name : MyNameDisplay)
             for(int counter = 0; counter < name.length(); counter++)
 
             System.out.println(scounter + "[ " + name.substring(0, name.length()-counter)+ " ]");
 
 
            }
 
 
 
//***********************************************************************************************************************
 
    public static void PrintAllUpper(String MyNameUpper[]) //Method for printing name all in upper case.
         {
           System.out.println("\nPrinting my name in upper case.");
           for(String name : MyNameUpper)
           System.out.println(name.toUpperCase());
         }
 
    public static void PrintAllLower(String MyNameLower[]) //Method for printing name all in lower case.
         {
           System.out.println("\nPrinting my name in lower case.");
           for(String name : MyNameLower)
           System.out.println(name.toLowerCase());
         }
 
   public static void PrintNoSpaces(String MyNameNoSpace[]) //Method for printing the name without spaces.
         {
           System.out.println("\nPrinting my name with no space.");
           for(String name : MyNameNoSpace)
           for(int i=0;i < MyNameNoSpace.length;i++)
           System.out.println(name.replaceAll(" ", ""));
         }
  public static void UpperVtoLowerC(String MyNameUpperVtoLowerC[]) //Method for printing the name with consonants in lower case and vowels in upper case.
         {
           String NewName = "hEctOr & jOrgE % fArInAs";
           System.out.println("\nPrinting my name with vowels in upper case and consonants in lower case.");
           for(String name : MyNameUpperVtoLowerC)
           System.out.println(name.replaceAll(name, NewName));
         }
  public static void UpperCtoLowerV(String MyNameUpperCtoLowerV[]) //Method for printing the name with consonants in upper case and vowels in lower case.
         {
           String NewName = "HeCToR & JoRGe % FaRiNaS";
           System.out.println("\nPrinting my name with vowels in lower case and consonants in upper case.");
           for(String name : MyNameUpperCtoLowerV)
           System.out.println(name.replaceAll(name, NewName));
         }
public static void PrintNameBackwards(String MyNameReverse[]) //Method for printing the name backwards.
        {
          System.out.println("\nPrinting my name in reverse.");
          for(String name : MyNameReverse)
          for (int i = name.length()-1; i >= 0; i--)
	  System.out.print(name.charAt(i));
          System.out.println("");
 
         }
public static void PrintNameAscii(String MyNameAscii[]) //Method for ptinting the name in ASCII.
       {
           System.out.println("\nPrinting my name in ASCII values.");
        for(String name : MyNameAscii)
        for (int i = 0; i<name.length();i++)
        System.out.println("The ASCII value for " + name.charAt(i) + " is: " + (int)name.charAt(i));
       }
 
 
 
}

Originally Posted by dlorde

Your name is a single String, so why are you passing an array of Strings to your method?

I did that because I guess thats what he wants? Maybe I am wrong, Here are the instructions :
At the main method, create a single dimension array containing your
"first name $ middle name % last name and ONE space"
i.e. "George & Washington % Rodriguez "

Again, thank you and sorry for the long post.

while(scounter > 0)
{
scounter--;
}

What is the purpose of this loop? It really only wastes time by repeatedly subtracting one from the variable until it is zero. Please explain.

Look at the first two lines of the desired output:

32 [George $ Washington % Rodriguez ]
31 [George $ Washington % Rodriguez]

What changes from the first line to the second line?
Now what do you need in your code to make those changes? Just think about how to change the first line to the second line for now.
Later when you have what to do for those two lines, Then think about the changes from the second line to the third line

Originally Posted by Norm

What is the purpose of this loop? It really only wastes time by repeatedly subtracting one from the variable until it is zero. Please explain.

Look at the first two lines of the desired output:


What changes from the first line to the second line?
Now what do you need in your code to make those changes? Just think about how to change the first line to the second line for now.
Later when you have what to do for those two lines, Then think about the changes from the second line to the third line

I was trying to mess with the loops and see.It goes down from 32 to 31 and so on. I need a loop that goes from String.length to 0 I guess?

What is the number at the start of the printout supposed to be?
Where is that information available? Is there method that will obtain it for you?

Using a for loop, display to the screen, the string containing your name so that each loop will NOT contain the last character on the previous line, with the length of the string being printed, and the string surrounded by square brackets []..

Those are the instructions. I have this but it only prints out a 1 on all lines.

for(int scounter = MyNameDisplay.length; scounter > 0; scounter--)

What is the number at the start of the printout supposed to be?
Where is that information available? Is there method that will obtain it for you?

You should read your instructions, figure out the answer to my question and give me just that answer.
Repeating the whole of your instructions means that you must not understand what the number is or you could tell me. Do you know what it is? Do you understand the instructions?

I posted the instruction in my previous post. Yes I understand them. I need to print out my name eliminating the last character on each line until it reaches to the first one and printing out the length of each string (which is the only thing I need) For Example:
3[John]
2[Joh]
1[Jo]
0[J]

Where can your code get the length so it can print it? Isn't that length used in the call to the substring method?

I am trying to get scounter = String.length then substract scounter 1 (scounter --) each time??

public static void DisplayName(String MyNameDisplay[]) //Method for displaying my name with one character less in the nextline.
            {
             System.out.println("\nDisplaying my name substracting one character.");
             for(int scounter = MyNameDisplay.length; scounter > 0; scounter--)
             for (String name : MyNameDisplay)
             for(int counter = 0; counter < name.length(); counter++)
 
             System.out.println(scounter + "[ " + name.substring(0, name.length()-counter)+ " ]");
 
 
            }

What does that give you?
Why create a new value when the expression being used in the substring method has the correct value?

I am using the substring for the name which starts at 0 and subtracts on at the end from each line , not for the length of each line on the left, which I want scounter to do that correct??

Is the value used in the substring method the value that you want to print at the start of the line?
What I'm suggesting is that you should only compute a value once and use it as needed Vs computing it in different ways in different places.

yeah i get what you are saying with the values.