Letter Pyramid

I'm not a C programmer, but I can tell you what you need to do.

Firstly you are always printing 26 lines, but you only need x where x is the position of the letter input in the alphabet (well call this Z). This can be done by getting the ascii code of the letter. In VB there is an ASC function which does this ASC(Z). You then subtract the ASCII code for "A" and add 1. Noting that the input character is either upper or lower case, so convert it to upper case before calculating the number of rows needed. well call this number z

The next step is to work out the character to print. this will start at A, increment to the selected letter and then decrease back to A again. This can be done by using a variable lets call it x, if it is <= z then print char(x) else print char(2 * z - x)

I hope that this helps

I thiink it would be easier to make a string array of the alphabet, and get the index in it of the letter you want.  You could do ASCII decimal number calculations, but I bet your teacher is looking more for how to loop based on a string array.

So something like
String[] alphlist = {"A","B","C"}; // you get the idea

Then loop through alphlist until you hit the letter that equals the input.  If you have to handle lower case vs upper case -- that is, if "e" is the input and you have to find "E" then you can make 2 string arrays, or you could use the String method equalsIgnoreCase .

Once you find the index in the array of the input letter, you know the strudcture of what you will be producing.  Use the same alphabet string array to print out the pyramid lines.

String[] alphaList = {"A", "B", "C", "D", (all the way to 'Z'), "Z"};

Select allOpen in new window

userInput = Character.toUpperCase(userInput);// To capitalize letter
			if (userInput == alphaList[0])

Select allOpen in new window

        String input = null;
	char inChar;
	char[] ch = {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'};

	Scanner s = new Scanner(System.in);

	do{
		System.out.print("Input a letter :");

		input = s.next();
		inChar = input.charAt(0);

	}while((input.length()>1)&&!(input.equals("exit")));

	if(!input.equals("exit")){

		for(int d =0;d<=(int)inChar-97;d++){ // obtain (print) all chars up to and including the one entered.
			System.out.print(ch[d]);
		}
	}

Select allOpen in new window

char[] alphaList = {'A', 'B', 'C', 'D', (...all the way to 'Z'), 'Z'};

Select allOpen in new window

userInput = Character.toUpperCase(userInput);// To capitalize letter
			if (userInput == alphaList[0])

Select allOpen in new window

else
				{
				(arr[i]++);
				}

Select allOpen in new window

I can't think of how to write the code to, first search the array to find the char that the user entered,

	String input = null;
	char inChar;
	
	String alphabet = new String("ABCDEFGHIJKLMNOPQRSTUVWXYZ");

	Scanner s = new Scanner(System.in);

	do{
		System.out.print("Input a letter :");

		input = s.next();
		inChar = input.charAt(0);

	}while((input.length()>1)&&!(input.equalsIgnoreCase("exit")));
	

	if(!input.equals("exit")){
	int pointer = 1;
		for(int y=0;y<=alphabet.indexOf(Character.toUpperCase(inChar));y++){

			System.out.println(alphabet.substring(0,pointer++));
			
		}
	}

Select allOpen in new window

import java.util.*;// For using Scanner class for input

public class LetterPyramid
{      
      public static void main(String[] args)// Main method
      {         
            char userInput = ' ';// Declare and initialize variables
            char line = ' ', space = 0, letter = 0;
            Scanner cin = new Scanner(System.in);
            System.out.print("Enter a single letter: ");// Prompt for single character
            userInput = cin.next().charAt(0);// Get single character
            
            if (Character.isLetter(userInput))// Check to see if input is a letter
            {
                  userInput = Character.toUpperCase(userInput);// To capitalize letter
                  for(line = 'A'; line <= userInput; line++)
                  {
                        for(space = userInput; space > line; space--)
                        {
                              System.out.print(' ');// Displays one space
                        }
                        for(letter = 'A'; letter < line; letter++)        
                        {                                                
                              System.out.print(letter);                
                        }
                        for(letter = line; letter >= 'A'; letter--)
                        {
                              System.out.print(letter);
                        }
                        System.out.println();
                  }
            }
            else
            {
                  System.out.println("Error: Invalid letter " + userInput);// If character is not valid letter display error
            }            
      }
}