PAGE-1 : STAR PATTERN PROGRAMS

Print Patterns of Stars

To print patterns of stars (*) in Java Programming, you have to use two loops, first is outer loop and the second is inner loop. 

The outer loop is responsible for rows and the inner loop is responsible for columns.You will need spaces to adjust your pattern accordingly.

How many levels you would have will be decided by the user input. You can print this kind of pattern by using print() and println() method from System.out object. 

Explanation of Code
Scanner s=new Scanner(System.in): are used for receive input from keyboard.
nextInt(): method are used for get integer type value from keyboard.
System.out.println("....."): are used for display message on screen or console.
System.out.print("....."): are used for display message on screen or console but cursor not move in new line.

System.out.println("....."): are used for display message on screen or console cursor move in new line.

Pattern-1 :

package com.starpattern;
import java.io.BufferedReader;
import java.io.InputStreamReader;

public class StarPatternProgram1 {
public static void main(String[] args) {
InputStreamReader istream = new InputStreamReader(System.in);
BufferedReader read = new BufferedReader(istream);
System.out.print("Enter Pattern Size : ");
int num = 0;
try {
num = Integer.parseInt(read.readLine());
} catch (Exception Number) {
System.out.println("Invalid Number!");
}

int i, j;
for (i = 0; i < num; i++) {
for (j = 0; j <= i; j++) {
System.out.print("* ");
}
System.out.println();
}
}
}

OUTPUT : 

Enter Pattern Size : 5
* 
* * 
* * * 
* * * * 

* * * * * 

Pattern-2 :

package com.starpattern;
import java.io.BufferedReader;
import java.io.InputStreamReader;

public class StarPatternProgram2 {
public static void main(String[] args) {
{
InputStreamReader istream = new InputStreamReader(System.in);
BufferedReader read = new BufferedReader(istream);
System.out.print("Enter Pattern Size : ");
int num = 0;
try {
num = Integer.parseInt(read.readLine());
} catch (Exception Number) {
System.out.println("Invalid Number!");
}
{
for (int i = 0; i < num; i++) {
for (int j = 0; j < i; j++)
System.out.print(" ");
for (int k = 0; k < num - i; k++) {
System.out.print("*");
}
System.out.println();

}

}
}
}
}

OUTPUT : 

Enter Pattern Size : 5
*****
 ****
  ***
   **

    *

Pattern-3 :

package com.starpattern;

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class StarPatternProgram3 {
public static void main(String[] args) {
InputStreamReader istream = new InputStreamReader(System.in);
BufferedReader read = new BufferedReader(istream);
System.out.print("Enter Pattern Size : ");
int num = 0;
try {
num = Integer.parseInt(read.readLine());
} catch (Exception Number) {
System.out.println("Invalid Number!");
}

for (int i = 0; i < num; i++) {
for (int k = 0; k < num - i; k++) {
System.out.print("*");
}
System.out.println();
}

}
}

OUTPUT : 

Enter Pattern Size : 5

*****

****

***

**

*

Pattern-4 :

package com.starpattern;

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class StarPatternProgram4 {
public static void main(String[] args) {
InputStreamReader istream = new InputStreamReader(System.in);
BufferedReader read = new BufferedReader(istream);
System.out.print("Enter Pattern Size : ");
int num = 0;
try {
num = Integer.parseInt(read.readLine());
} catch (Exception Number) {
System.out.println("Invalid Number!");
}
for (int i = 0; i < num; i++) {
for (int space = 0; space < num - i; space++)
System.out.print(" ");
for (int count = 0; count < (2 * i + 1); count++)
System.out.print("*");
System.out.println();
}

}

}

OUTPUT : 

Enter Pattern Size : 5
     *
    ***
   *****
  *******

 *********

Pattern-5 :

package com.starpattern;

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class StarPatternProgram5 {
public static void main(String[] args) {
InputStreamReader istream = new InputStreamReader(System.in);
BufferedReader read = new BufferedReader(istream);
System.out.print("Enter Pattern Size : ");
int num = 0;
try {
num = Integer.parseInt(read.readLine());
} catch (Exception Number) {
System.out.println("Invalid Number!");
}
for (int i = 0; i < num; i++) {
for (int space = 0; space < num - i; space++)
System.out.print(" ");
for (int count = 0; count < (2 * i + 1); count++)
System.out.print("*");
System.out.println();
}
for (int k = num - 1; k > 0; k--) {
for (int j = 0; j <= num - k; j++)
System.out.print(" ");
for (int i = 0; i < 2 * k - 1; i++)
System.out.print("*");
System.out.println();
}

}
}

OUTPUT : 

Enter Pattern Size : 5

      *
    ***
   *****
  *******
 *********
  *******
   *****
    ***
     *

Pattern-6 :

package com.starpattern;

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class StarPatternProgram6 {
public static void main(String[] args) {
InputStreamReader istream = new InputStreamReader(System.in);
BufferedReader read = new BufferedReader(istream);
System.out.print("Enter Pattern Size : ");
int num = 0;
try {
num = Integer.parseInt(read.readLine());
} catch (Exception Number) {
System.out.println("Invalid Number!");
}

for (int i = 0; i < num; i++) {
for (int space = 0; space < num - i; space++)
System.out.print(" ");
for (int count = 0; count < (2 * i + 1); count++)
if (count == 0 || count == 2 * i)
System.out.print("*");
else
System.out.print(" ");
System.out.println();
}
for (int k = num - 1; k > 0; k--) {
for (int j = 0; j <= num - k; j++)
System.out.print(" ");
for (int i = 0; i < 2 * k - 1; i++)
if (i == 0 || i == 2 * k - 2)
System.out.print("*");
else
System.out.print(" ");
System.out.println();
}

}
}

OUTPUT : 

Enter Pattern Size : 5

     *

    * *

   *   *

  *     *

 *       *

  *     *

   *   *

    * *

     *