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Java pattern programs enhance the concepts of coding, logic, and loops. The main question in the Java interview is to test the logic and thinking of the programmer. We can print a Java pattern program in different designs but we must have a deep knowledge of the Java loop, such as for loop do-while loop.

We have grouped the Java pattern programs into three categories.

• Start Pattern
• Number Pattern
• Character Pattern

Example – Star Pattern

Program to print Right Triangle Star Pattern

public class RightTrianglePattern {
  
  public static void main(String args[]) {
    
    int i,j;        // for columns
    int row = 8;   // row denotes the number of rows you want to print
    
    
    for (i = 0; i < row; i++) {
      
      for (j = 0; j <= i; j++) {
        // prints stars
        System.out.print("* ");
      }
      
      System.out.println(); // for new line after printing each line 
    }
  }
}

Output

Print Left Triangle Star Pattern

public class LeftTriangle {
  public static void main(String args[]) {
    
    int i, j;    // for columns
    int row = 8; // the number of rows you want to print
    for (i = 0; i < row; i++) {
      for (j = 2 * (row - i); j >= 0; j--) {
        // prints space between two stars
        System.out.print(" ");
      }
      for (j = 0; j <= i; j++) {
        // prints star
        System.out.print("* ");
      }
      System.out.println();
    }
  }
}

Output

Print Pyramid Star Pattern

public class PyramidPattern {
  public static void main(String args[]) {

    int i, j; // for columns
    int row = 8; // number of rows you want to print

    for (i = 0; i < row; i++) {

      for (j = row - i; j > 1; j--) {
        // prints space between two stars
        System.out.print(" ");
      }

      for (j = 0; j <= i; j++) {
        // prints star
        System.out.print("* ");
      }
      System.out.println();
    }
  }
}

Output

Example – Number Pattern

Program to print Number pattern – 1

public class NumberPattern1 {
  public static void main(String args[]) {
    int i, j, num;
    int max = 9;
    
    // loop for rows
    for (i = 0; i < max; i++) {
      num = 1;
      // loop for columns
      for (j = 0; j <= i; j++) {
        // prints num
        System.out.print(num + " ");
        num=num+1;
      }
      
      System.out.println();
    }
  }
}

Output

Print Number pattern – 2

public class NumberPattern2 {
  public static void main(String[] args) {
    int i, j, k = 1;

    for (i = 1; i <= 9; i++) {

      for (j = 1; j < i + 1; j++) {
        // prints value
        System.out.print(k++ + " ");
      }
      System.out.println();
    }
  }
}

Output

Print Number Pattern – 3

public class NumberPattern3 {
  public static void main(String args[]) {
    int rows = 8;
    for (int i = 1; i <= rows; i++) {
      int num = i;
      for (int j = 1; j <= i; j++) {
        System.out.print(num + " ");
        num = num + rows - j;
      }
      System.out.println();
    }
  }
}

Output

Example – Character Pattern

Program to print Right Triangle Alphabetic Pattern

public class RightAlphabaticPattern {
  public static void main(String[] args) {
    int alphabet = 65; // ASCII value of capital A
    for (int i = 0; i <= 7; i++) {
      for (int j = 0; j <= i; j++) {

        System.out.print((char) (alphabet + j) + " ");
      }
      System.out.println();
    }
  }
}

Output

Print Repeating Alphabet Pattern

public class RepeatingPattern {
  public static void main(String[] args) {
    int letter = 65; 
    
    for (int i = 0; i <= 8; i++) {
      for (int j = 0; j <= i; j++) {
        System.out.print((char) letter + " ");
      }
      letter=letter+1;
      System.out.println();
    }
  }
}

Output