Java Apni Kak

For Loops:

package com.company;

import java.util.*;

public class Main {

    public static void main(String[] args) {
        //Print sum of n numbers input taken by users, this code will give each step result

        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();

        int sum = 0;
/*  How loops works
*   sum=0, 0+1, where 1= i
*   sum=1, 1+2, where 2= i
*   sum=2, 3+3,  where 3(last one)= i
*   sum=6, 6+4, where 4= i
*   sum=10, 10+5, where 5= i
*   i Value reaches to condition
*
*  */
        for (int i = 1; i <= n; i++) {
            sum = sum+i;
            System.out.println(sum);
        }

    }
}

public class Main {

    public static void main(String[] args) {
        //Print sum of n numbers input taken by users, this code will one result

        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();

        int sum = 0;
/*  How loops works
*   sum=0, 0+1, where 1= i
*   sum=1, 1+2, where 2= i
*   sum=2, 3+3,  where 3(last one)= i
*   sum=6, 6+4, where 4= i
*   sum=10, 10+5, where 5= i
*   i Value reaches to condition
*
*  */
        for (int i = 1; i <= n; i++) {
            sum = sum+i;
            
        }
            System.out.println(sum);
    }
}

Table of N number

package com.company;

import java.util.*;

public class Main {

    public static void main(String[] args) {
        //Print the table of n number input taken by users

        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();

        int mul ;

        for (int i = 1; i <= 10; i++) {
             mul=n*i;
            System.out.println(mul);
        }

    }
}

Print all number till n number

package com.company;

import java.util.*;

public class Main {

    public static void main(String[] args) {
        //Print all numbers till n.

        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();

        for (int i = 0; i <= n; i++) {

            System.out.println(i);
        }

    }
}

Print the even number till a number

package com.company;

import java.util.*;

public class Main {

    public static void main(String[] args) {
        //Print all numbers till n.

        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();

        for (int i = 2; i<=n; i++) {

        if(i%2==0){
            System.out.println(i);
        }
       
        }

    }
}

Check prime or not 

Method 1 without 1 number case:

package com.company;

import java.util.*;

public class Main {

    public static void main(String[] args) {
        //Check number prime or not input taken by users, https://www.youtube.com/watch?v=u9NT9kjNRys
       Scanner sc = new Scanner(System.in);
       System.out.println("Enter your number: ");
       int no = sc.nextInt();
        int temp =0;
       for(int i = 2; i<=no-1; i++)
       {

           if(no%i==0){
               temp=temp+1;
           }
       }
          
           if(temp==0){
               System.out.println(no+" is a prime number");
           }
           else {
               System.out.println(no+" is not prime number");
           }
       }

    }

Prime number check with 1 number condition

package com.company;

import java.util.*;

public class Main {

    public static void main(String[] args) {
        //Check number prime or not input taken by users, https://www.youtube.com/watch?v=u9NT9kjNRys
       Scanner sc = new Scanner(System.in);
       System.out.println("Enter your number: ");
        int n = sc.nextInt();
        boolean isPrime = true;
       for(int i =2; i<n; i++){
           if(n%i==0){
               isPrime = false;
               break;
           }
       }
       if(n<2) isPrime = false;
       System.out.println("Is a prime number? "+ isPrime);
       }

    }

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