Alphabet Pattern in Java

In Java, just like pyramid and triangle patterns, alphabet patterns are also given by most of the interviewers to the developer for writing codes. Patterns of alphabets such as A, B, C, …….. are designed based on the user given height of the pattern. The width of the pattern is calculated with the help of the user given input h.

We will print all the alphabets from A to Z within a single program. We will create different methods to print pattern for each and every alphabet.

Let's implement the code to print pattern for each and every alphabet.

AlphabetPatternProgram.java

//import required classes and package, if any
import java.util.Scanner;
//create AlphabetPatternProgram class to print the alphabet
public class AlphabetPatternProgram {
	// create absValue() method to get absolute value
	public static int absValue(int n) {
		if(n < 0) {
			return (-1 * n);
		}else {
			return n;
		}
	}
	// create drawPatternA() method to print the pattern of 'A'
	public static void drawPatternA(int h, int w){
		int n = w / 2;
		for (int i = 0; i < h; i++) {
			for (int j = 0; j <= w; j++) {
				if (j == n || j == (w - n) || (i == h / 2 && j > n && j < (w - n))) {
					System.out.printf("*");
				} else {
					System.out.printf(" ");
				}
	        }
	        System.out.printf("\n");
	        n--;
		}
	}
	// create drawPatternB() method to print the pattern of 'B'
	public static void drawPatternB(int h, int w){
		int mid = (h / 2);
		for(int i = 0; i < h; i++) {
			System.out.printf("*");
			for(int j = 0; j < w; j++) {
				if((i == 0 || i == h - 1 || i == mid) && j < (w - 2)) {
					System.out.printf("*");
				} else if (j == (w - 2) && !(i == 0 || i == h - 1 || i == mid)) {
	                System.out.printf("*");
				} else {
					System.out.printf(" ");
				}
			}
			System.out.printf("\n");
		}
	}
	// create drawPatternC() method to print the pattern of 'C'
	public static void drawPatternC(int h){
		for(int i = 0; i < h; i++) {
			System.out.printf("*");
			for (int j = 0; j < (h - 1); j++) {
				if (i == 0 || i == h - 1) {
					System.out.printf("*");
				} else {
					continue;
				}
	        }
	        System.out.printf("\n");
		}
	}
	// create drawPatternD() method to print the pattern of 'D'
	public static void drawPatternD(int h){
		for(int i = 0; i < h; i++) {
			System.out.printf("*");
			for (int j = 0; j < h; j++) {
				if((i == 0 || i == h - 1) && j < h - 1) {
					System.out.printf("*");
				}else if (j == h - 1 && i != 0 && i != h - 1) {
					System.out.printf("*");
				}else {
					System.out.printf(" ");
		        }
		    }
			System.out.printf("\n");
		}
	}
	// create drawPatternE() method to print the pattern of 'E'
	public static void drawPatternE(int h){
		for (int i = 0; i < h; i++) {
			System.out.printf("*");
			for (int j = 0; j < h; j++) {
				if ((i == h / 2 && j <= h / 2) || (i == 0 || i == h - 1)) {
					System.out.printf("*");
				} else {
					continue;
				}
			}
			System.out.printf("\n");
	    }
	}
	// create drawPatternF() method to print the pattern of 'F'
	public static void drawPatternF(int h){
		for (int i = 0; i < h; i++) {
			System.out.printf("*");
			for (int j = 0; j < h; j++) {
				if ((i == h / 2 && j <= h / 2) || i == 0) {
					System.out.printf("*");
				} else {
					continue;
				}
			}
			System.out.printf("\n");
	    }
	}
	// create drawPatternG() method to print the pattern of 'G'
	public static void drawPatternG(int h, int w){
		w--;
		for(int i = 0; i < h; i++) {
			for(int j = 0; j < w; j++) {
				if((j == 0 || j == w -1 ) && (i == 0 || i == h -1)) {
					System.out.printf(" ");
				}else if(j == 0) {
					System.out.printf("*");
				}else if(i == 0 && j <= h) {
					System.out.printf("*");
				}else if(i == h / 2 && j > h / 2) {
					System.out.printf("*");
				}else if(i > h / 2 && j == w - 1) {
					System.out.printf("*");
				}else if(i == h - 1 && j < w) {
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			System.out.printf("\n");
		}
	}
	// create drawPatternH() method to print the pattern of 'H'
	public static void drawPatternH(int h){
		for(int i = 0; i < h; i++) {
			System.out.printf("*");
			for(int j = 0; j < h; j++) {
				if((j == h - 1) || (i == h / 2)) {
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			System.out.printf("\n");
		}
	}
	// create drawPatternI() method to print the pattern of 'I'
	public static void drawPatternI(int h){
		
		for(int i = 0; i < h; i++) {
			for(int j = 0; j < h; j++) {
				if((i == h - 1) || (i == 0)) {
					System.out.printf("*");
				}else if(j == h / 2){
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			System.out.printf("\n");
		}
	}
	// create drawPatternJ() method to print the pattern of 'J'
	public static void drawPatternJ(int h){
		
		for(int i = 0; i < h; i++) {
			for(int j = 0; j < h; j++) {
				if((i == h - 1) && (j > 0 && j < h - 1)) {
					System.out.printf("*");
				}else if((j == h - 1 && i != h - 1) || (i > (h / 2) - 1 && j == 0 && i != h - 1 )){
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			System.out.printf("\n");
		}
	}
	// create drawPatternK() method to print the pattern of 'K'
	public static void drawPatternK(int h){
		int mid = h / 2;
		int temp = mid;
		
		for(int i = 0; i < h; i++) {
			System.out.printf("*");
			for(int j = 0; j <= mid; j++) {
				if(j == absValue(temp)) {
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			System.out.printf("\n");
			temp = temp - 1;
		}
	}
	// create drawPatternL() method to print the pattern of 'L'
	public static void drawPatternL(int h){
		for(int i = 0; i < h; i++) {
			System.out.printf("*");
			for(int j = 0; j <= h; j++) {
				if(i == h - 1) {
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			System.out.printf("\n");
		}
	}
	// create drawPatternM() method to print the pattern of 'M'
	public static void drawPatternM(int h){
		int count = 0;
		for(int i = 0; i < h; i++) {
			System.out.printf("*");
			for(int j = 0; j <= h; j++) {
				if(j == h) {
					System.out.printf("*");
				}else if(j == count || j == (h - count - 1)){
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			if(count == h / 2) {
				count = -99999;
			}else {
				count = count + 1;
			}
			System.out.printf("\n");
		}
	}
	// create drawPatternN() method to print the pattern of 'N'
	public static void drawPatternN(int h){
		int count = 0;
		for(int i = 0; i < h; i++) {
			System.out.printf("*");
			for(int j = 0; j <= h; j++) {
				if(j == h) {
					System.out.printf("*");
				}else if(j == count){
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			count = count + 1;
			System.out.printf("\n");
		}
	}
	// create drawPatternO() method to print the pattern of 'O'
	public static void drawPatternO(int h){
		
		int spc = h / 3;
		int w = h / 2 + h / 5 + spc + spc;
		for(int i = 0; i < h; i++) {
			for(int j = 0; j <= w; j++) {
				if(j == (w - absValue(spc)) || j == absValue(spc)) {
					System.out.printf("*");
				}else if((i == 0 || i == (h - 1)) && j > absValue(spc) && j < (w - absValue(spc))){
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			if(spc != 0 && i < h / 2) {
				spc = spc - 1;
			}else if(i >= (h / 2 + h / 5)) {
				spc = spc - 1;
			}
			System.out.printf("\n");
		}
	}
	// create drawPatternP() method to print the pattern of 'P'
	public static void drawPatternP(int h){
		
		for(int i = 0; i < h; i++) {
			System.out.printf("*");
			for(int j = 0; j <= h; j++) {
				if((i == 0 || i == h / 2) && j < h - 1) {
					System.out.printf("*");
				}else if(i < h / 2 && j == h - 1 && i != 0){
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			System.out.printf("\n");
		}
	}	
	// create drawPatternQ() method to print the pattern of 'Q'
	public static void drawPatternQ(int h){
		
		int temp = h;
		
		// call drawPatternO() method to print pattern of 'O'
		drawPatternO(h);
		for(int i = 0; i < h / 2; i++) {
			for(int j = 0; j <= temp; j++) {
				if(j == temp) {
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			System.out.printf("\n");
			temp = temp + 1;
		}
	}
	// create drawPatternR() method to print the pattern of 'R'
	public static void drawPatternR(int h, int w){
		
		int mid = h / 2;
		
		for(int i = 0; i < h; i++) {
			System.out.printf("*");
			for(int j = 0; j < w; j++) {
				if((i == 0 || i == mid) && j < (w - 2)) {
					System.out.printf("*");
				}else if(j == (w - 2) && !(i == 0 || i == mid)){
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			System.out.printf("\n");
		}
	}
	// create drawPatternS() method to print the pattern of 'S'
	public static void drawPatternS(int h){
		
		for(int i = 0; i < h; i++) {
			for(int j = 0; j < h; j++) {
				if((i == 0 || i == h / 2 || i == h - 1)) {
					System.out.printf("*");
				}else if(i < h / 2 && j == 0){
					System.out.printf("*");
				}else if(i > h / 2 && j == h - 1){
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			System.out.printf("\n");
		}
	}
	// create drawPatternT() method to print the pattern of 'T'
	public static void drawPatternT(int h){
		
		for(int i = 0; i < h; i++) {
			for(int j = 0; j < h; j++) {
				if(i == 0) {
					System.out.printf("*");
				}else if(j == h / 2){
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			System.out.printf("\n");
		}
	}
	// create drawPatternU() method to print the pattern of 'U'
	public static void drawPatternU(int h){
		
		for(int i = 0; i < h; i++) {
			if(i != 0 && i != h - 1) {
				System.out.printf("*");
			}else {
				System.out.printf(" ");
			}
			for(int j = 0; j < h; j++) {
				if(((i == h - 1) && j >= 0 && j < h - 1)) {
					System.out.printf("*");
				}else if(j == h - 1 && i != 0 && i != h - 1){
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			System.out.printf("\n");
		}
	}
	// create drawPatternV() method to print the pattern of 'V'
	public static void drawPatternV(int h, int w){
		
		int count = 0;
		
		for(int i = 0; i < h; i++) {
			for(int j = 0; j <= w; j++) {
				if(j == count || j == (w - count - 1)) {
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			count = count + 1;
			System.out.printf("\n");
		}
	}
	// create drawPatternW() method to print the pattern of 'W'
	public static void drawPatternW(int h){
		
		int count = h / 2;
		
		for(int i = 0; i < h; i++) {
			System.out.printf("*");
			for(int j = 0; j <= h; j++) {
				if(j == h) {
					System.out.printf("*");
				}else if((i >= h / 2) && (j == count || j == h - count - 1)){
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			if(i >= h / 2) {
				count = count + 1;
			}
			System.out.printf("\n");
		}
	}
	// create drawPatternX() method to print the pattern of 'X'
	public static void drawPatternX(int h){
		
		int count = 0;
		
		for(int i = 0; i <= h; i++) {
			for(int j = 0; j <= h; j++) {
				if(j == count || j == h - count) {
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			count = count + 1;
			System.out.printf("\n");
		}
	}
	// create drawPatternY() method to print the pattern of 'Y'
	public static void drawPatternY(int h){
		
		int count = 0;
		
		for(int i = 0; i <= h; i++) {
			for(int j = 0; j < h; j++) {
				if(j == count || j == h - count && i <= h / 2) {
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			if(i < h / 2) {
				count = count + 1;
			}
			System.out.printf("\n");
		}
	}
	// create drawPatternZ() method to print the pattern of 'Z'
	public static void drawPatternZ(int h){
		
		int count = h - 1;
		
		for(int i = 0; i < h; i++) {
			for(int j = 0; j < h; j++) {
				if(i == 0 || i == h - 1 || j == count) {
					System.out.printf("*");
				}else {
					System.out.printf(" ");
				}
			}
			count = count - 1;
			System.out.printf("\n");
		}
	}
	// main() method start
	public static void main(String args[]){ 
	
		char c; 
	
		int n;
		
		// create an instance of Scanner class
		Scanner sc = new Scanner(System.in);
	
		System.out.println("Enter height of the pattern:");
		n = sc.nextInt();
		
		System.out.println("Enter character from A-Z to print:");
		c = sc.next().charAt(0);
	
		// close Scanner class object
		sc.close();
	
		switch (c) {
			case 'A':
				drawPatternA(n, (2 * n) - 1); 
				break;
			case 'B':
				drawPatternB(n, (2 * n) - 1); 
				break;
			case 'C':
				drawPatternC(n);
				break;
			case 'D':
				drawPatternD(n);
				break;
			case 'E':
				drawPatternE(n);
				break;
			case 'F':
				drawPatternF(n);
				break;
			case 'G':
				drawPatternG(n, (2 * n) - 1); 
				break;
			case 'H':
				drawPatternF(n);
				break;
			case 'I':
				drawPatternF(n);
				break;
			case 'J':
				drawPatternF(n);
				break;
			case 'K':
				drawPatternF(n);
				break;
			case 'L':
				drawPatternF(n);
				break;
			case 'M':
				drawPatternF(n);
				break;
			case 'N':
				drawPatternF(n);
				break;
			case 'O':
				drawPatternF(n);
				break;
			case 'P':
				drawPatternF(n);
				break;
			case 'Q':
				drawPatternF(n);
			    break;
			case 'R':
				drawPatternR(n, (2 * n) - 1); 
			    break;
			case 'S':
				drawPatternF(n);
			    break;
			case 'T':
				drawPatternF(n);
			    break;
			case 'U':
				drawPatternF(n);
			    break;
			case 'V':
				drawPatternV(n, (2 * n) - 1); 
			    break;
			case 'W':
				drawPatternF(n);
			    break;
			case 'X':
				drawPatternF(n);
			    break;
			case 'Y':
				drawPatternF(n);
			    break;
			case 'Z':
				drawPatternF(n);
			    break;
		}
	}
}

Output: