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Java Exercises: Compute the sum of the prime numbers till 100

Java Basic: Exercise-66 with Solution

Write a Java program to Compute the sum of the prime numbers till 100.

Pictorial Presentation:

Java Basic Exercises: Compute the sum of the prime numbers till 100

Sample Solution:

Java Code:

import java.util.*;
 public class Exercise66 {
 public static void main(String[] args)
 {
    int sum = 1;
	 int ctr = 0; 
	 int n = 0; 
    	
		while (ctr < 100) {
			n++; 
			if (n % 2 != 0) { 
			// check if the number is even
				if (is_Prime(n)) {
					sum += n; 					
				}
			}
                    ctr++; 	
		}
		System.out.println("\nSum of the prime numbers till 100: "+sum); 	
	 }
	
   	public static boolean is_Prime(int n) {
		for (int i = 3; i * i <= n; i+= 2) {
			if (n % i == 0) {
				return false; 
			}
		}
		return true;
	}
}

Sample Output: 

Sum of the prime numbers till 100: 1060

Flowchart:

Flowchart: Java exercises: Compute the sum of the first 100 prime numbers

Java Code Editor:

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Java: Tips of the Day

Execution of console commands:

Java allows you to execute console commands directly from code using a class Runtime. It is very important not to forget about exception handling.

For example, let's try to open a PDF file through a Java terminal:

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
  
public class ShellCommandExec {
  
  public static void main(String[] args) {
    String gnomeOpenCommand = "gnome-open //home//user//Documents//MyDoc.pdf";
  
    try {
      Runtime rt = Runtime.getRuntime();
      Process processObj = rt.exec(gnomeOpenCommand);
  
      InputStream stdin = processObj.getErrorStream();
      InputStreamReader isr = new InputStreamReader(stdin);
      BufferedReader br = new BufferedReader(isr);
  
      String myoutput = "";
  
      while ((myoutput=br.readLine()) != null) {
        myoutput = myoutput+"\n";
      }
      System.out.println(myoutput);
    }
    catch (Exception e) {
      e.printStackTrace();
    }
  }
}