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Prime Number in Java

In this section, you will learn how to get prime number between 1 to given number.

Prime Number in Java


This Java programming tutorial, we will be read how to get prime number between 1 to given number. First of all we have to define a class "PrimeNumber". Java I/O package has a input stream and a output stream in which input stream is used for reading the stream and memory allocating and the output stream used for writing bytes. As in this program we are going to insert certain instruction by creating buffer reader class. Here we have to create a buffer for the string class that can be used to instantiate a changeable object for storing and processing a string of character. Now use the ParseInt method for converting the parses the string argument and define 'num' as an integer.

Now applying in this program we use two 'for' loop. For loop will start from 1 to entered number. And another loop will start and divide it from 2 to less than those number. If number is divided by any number that means it is not prime otherwise prime number.

Here is the code of the Program


class PrimeNumber {
  public static void main(String[] argsthrows Exception{
  int i;
  BufferedReader bf = new BufferedReader(
new InputStreamReader(;
  System.out.println("Enter number:");
  int num = Integer.parseInt(bf.readLine());
  System.out.println("Prime number: ");
  for (i=1; i < num; i++ ){
  int j;
  for (j=2; j<i; j++){
  int n = i%j;
  if (n==0){
  if(i == j){
  System.out.print("  "+i);

 Download this Example.


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Orlan Villarino
March 30, 2012
Exam code java...

how am i going to run the example code of sorting
April 29, 2012
prime number

veri nice
J.ravi kumar
June 2, 2012
core java and advance java

excellent work
July 2, 2012

good solution
August 17, 2012

Sir, I am studing in MCM II but stil i don't have any cammand on java and i want to learn java very well. I kindly request to you plz guide me .
September 25, 2012
Technical programming

in this program you must typed in the whole numbes finishing when the negative number typed in. For each integer entered, the program should also print outthe number of primes found
Faisal khan
October 21, 2012
how does this work?

how does this code work? i mean it's ok but explain it how the code will run? qhats the method behind it? u got my point right?
April 14, 2013

if (n==0){ break; } what does it do?
July 15, 2012

import*; import java.util.Scanner; class prime { public static void main(String args[]) {Scanner sc=new Scanner(; System.out.print("enter the value="); int p=sc.nextInt(); if((p==2) || (p==3) || (p==5)) { System.out.println("the value is prime no."); } else if((p%2)==0||(p%3)==0||(p%5)==0) { System.out.println("the value is not prime no."); } else System.out.println("the value is prime no."); } }