Java Program to Check Prime Number - The Coding Shala

Home >> Java Programs >> Check Prime Number

 In this post, we will learn how to Check if a Given Number is a Prime Number or not in Java.

Java Program to Check Prime Number

A Prime Number is a number that is divisible by 1 and the number itself. For example, the number 5 is a Prime Number because it is divisible by 1 and 5 only. 

Note: Number 0 and 1 are not prime numbers.

Example 1:
Input: 7
Output: Prime Number

Example 2:
Input: 9
Output: Not a Prime Number

Java Program: 

// Java program to Check Prime Number

import java.util.Scanner;

public class Main {
	
	static boolean isPrime(int num) {
		if(num < 2) return false;
		
		//  basic for loop ==> for(int i = 2; i < num / 2; i++ )
		for(int i = 2; i * i <= num; i++) {
			if(num % i == 0) return false;
		}
		return true;
	}
	
	public static void main(String[] args) { 
		Scanner sc = new Scanner(System.in);
		
		// take input char
		System.out.println("Enter the Number: ");
		int num = sc.nextInt();
		
		if(isPrime(num)) {
			System.out.println(num + " is a Prime Number");
		} else {
			System.out.println(num + " is not a Prime Number");
		}
		
		sc.close();
	}
}

Output: 

Enter the Number: 
8
8 is not a Prime Number


Other Posts You May Like
Please leave a comment below if you like this post or found some errors, it will help me to improve my content.
By

Comments

Post a Comment

Popular Posts from this Blog

N-th Tribonacci Number Solution - The Coding Shala

Home >> Programming >> N-th Tribonacci Number  Hey there, welcome back to another post. In this post, we will learn how to solve the N-th Tribonacci Number problem and will implement its solution in Java. N-th Tribonacci Number Problem Statement The Tribonacci sequence Tn is defined as follows: T0 = 0, T1 = 1, T2 = 1, and Tn+3 = Tn + Tn+1 + Tn+2 for n >= 0. Given n, return the value of Tn.  Example 1:  Input: n = 4 Output: 4 Explanation: T_3 = 0 + 1 + 1 = 2 T_4 = 1 + 1 + 2 = 4 N-th Tribonacci Number Java Solution using Bottom-Up DP This problem is similar to the Fibonacci series. We can solve it using the Bottom-Up approach of dynamic programming. Time Complexity: O(n) Space Complexity: O(n) The space complexity can be reduced to O(1) by using variables to store the previous three values instead of using an array. Java Program:  class Solution { public int tribonacci( int n) { if (n == 0) return 0; ...
Read more

Java Program to Convert Binary to Decimal - The Coding Shala

Home >> Java Programs >> Convert Binary to Decimal  Hey there, welcome back to another post. In this post, we will learn how to convert Binary to Decimal in Java. Java Program to Convert Binary to Decimal You have given a binary number, convert it to a decimal number. Example:  Input: 101 Output: 5 Input: 111 Output: 7 Binary to Decimal Conversion in Java Approach We will the below formula to convert binary to decimal: decimal number = (2^0) * (rightmost digit) + (2^1) * (second rightmost digit) + ...  for example:  binary number = 110 decimal number = 2^0 * 0 + 2^1 * 1 + 2^2 * 1 = 1 * 0 + 2 * 1 + 4 * 1 = 0 + 2 + 4 = 6 Java Program:  import java.util.Scanner; /** * https://www.thecodingshala.com/ */ public class Main { public static void printDecimal( int num) { int decimal = 0; int twos = 1; // 2^0 = 1 initial value while (num > 0) { ...
Read more

Shell Script to Create a Simple Calculator - The Coding Shala

Home >> Scripting >> simple calculator Shell Script to Create a Simple Calculator Write a shell script to create a simple calculator using a switch-case statement? Code:  #! / bin / bash echo "simple calculator" sum = 0 i = "y" echo "enter first number" read n1 echo "enter second number" read n2 while [ $ i = "y" ] do echo "1.Addition" echo "2.Subtraction" echo "3.Multiplication" echo "4.Division" echo "Enter choice" read ch case $ch in 1 ) sum =$(echo " $n1 + $n2" | bc - l) echo "Addition is =" $ sum ;; 2 ) sum =$(echo "$n1 - $n2" | bc - l) echo "Sub is =" $ sum ;; 3 ) sum =$(echo "$n1 * $n2" | bc - l) echo "Mul is =" $ sum ;; 4 ) sum =$(echo "$n1 / $n2" | bc - l) echo "div is =" $ sum ;; * )echo "invalid choice" esac echo "Do y...
Read more

LeetCode - Shuffle the Array Solution - The Coding Shala

Home >> LeetCode >> Shuffle the Array  In this post, we will learn how to solve LeetCode's Shuffle the Array problem and will implement its solution in Java. Shuffle the Array Given the array nums consisting of 2n elements in the form [x1,x2,...,xn,y1,y2,...,yn]. Return the array in the form [x1,y1,x2,y2,...,xn,yn]. Example 1: Input: nums = [2,5,1,3,4,7], n = 3 Output: [2,3,5,4,1,7]  Explanation: Since x1=2, x2=5, x3=1, y1=3, y2=4, y3=7 then the answer is [2,3,5,4,1,7]. Example 2: Input: nums = [1,2,3,4,4,3,2,1], n = 4 Output: [1,4,2,3,3,2,4,1] Practice this problem on LeetCode: Click Here. Shuffle the Array Java Solution Approach 1: Using a new Array. Space complexity: O(n). Java Program:  class Solution { public int [] shuffle ( int [] nums , int n ) { int [] ans = new int [ 2 * n ]; int j = 0 ; for ( int i = 0 ; i < 2 * n ; i = i + 2 ){ ans [ i ] = nums [ j ]; ans...
Read more

LeetCode - Swap Nodes in Pairs Solution - The Coding Shala

Home >> LeetCode >> Swap Nodes in Pairs LeetCode - Swap Nodes in Pairs Solution In this post, you will learn how to solve LeetCode's Swap Nodes in Pairs problem with Java Solution. We will solve this problem using recursion and iteration. Given a linked list, swap every two adjacent nodes and return its head.  You may not modify the values in the list's nodes, only nodes itself may be changed. Example: Given 1->2->3->4, you should return the list as 2->1->4->3. Practice this problem on  LeetCode(Click Here). Swap Nodes in Pairs Java Solution Approach 1: Iterative Solution. Java Program:  /** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) { val = x; } * } */ class Solution { public ListNode swapPairs ( ListNode head ) { //check for null or 1 node if ( head == null || head . next == n...
Read more