Java program asking for 10 numbers and puts them in an array. How do I ask for input? Is my code correct so far?

Question

This program asks for the user to input 10 numbers and is converted into an int array. If the array is lucky (contains the numbers 7, 13, or 18) then it prints out the sum of all the numbers in the array. If it does not contain those then it is false and it only prints the sum of all the even numbers.

How do I correctly ask for this input? How do I get the sum of the even numbers in the array? Is any of the other code incorrect?

import java.util.Scanner;

public class FunArrays {

public static void main(String[] args) {
    // until you do user input, you should test your methods using "test" as the input.
    int[] test = {1,2,3,4,5,6,7}; 
    luckyNumber1 = {7};
    luckyNumber2 = {13};
    luckyNumber3 = {18};


    int[] a=new int[9];
    Scanner sc=new Scanner(System.in);
        System.out.println("Please enter numbers...");
        for(int j=0;j==9;j++)
        a[j]=sc.nextInt();

}

public static int sum(int [ ] value) {
      int i, total = 0;
      for(i=0; i<10; i++)
      {
          total = total + value[ i ];
      }

      return (total);
 }
public static int sumOfEvens (
public static boolean isLucky (int[] array) {

    if ( (int == luckyNumber1) || (int == luckyNumber2) || (int == luckyNumber3 )
        return true; 

    else
        return false
}

// write the static methods isLucky, sum, and sumOfEvens

}

Answer 1

You have an array of size 9. Instead it should be of size 10. So, Change the initialization to

int[] a=new int[10];

Use modulo operator % or remainder operator in Java to find out even or odd numbers.

    int evenSum = 0;
    for(int j=0;j<a.length;j++){
    if(a[j]%2 == 0){
       //even numbers
       evenSum = evenSum + a[j];
    }else{
       //odd numbers
      }
    }
    return evenSum;

Answer 2

  int[] a=new int[9];
    Scanner sc=new Scanner(System.in);
        System.out.println("Please enter numbers...");
        for(int j=0;j==9;j++)
        a[j]=sc.nextInt();

}

There's something wrong with your loop, it should be

for (int j = 0; j < 9; j++)

With this fix it should correctly prompt the users for 9 numbers. Change to 10 for the array and the loop it would takes in 10 number.

Answer 3

Sum of evens

static int sumOfEvens(int array[]) {
    int sum = 0;
    for(int i = 0; i < array.length; i++>) {
        if(array[i] % 2 == 0)
            sum += array[i];
    }
    return sum;
}

Input

for(int j = 0; j < a.length; j++)
    a[j] = sc.nextInt();

Answer 4

import java.util.Scanner;

public class MyMain1 {

    public static void main(String[] args) {
        // until you do user input, you should test your methods using "test" as
        // the input.
        int[] luckyNumbers = { 7, 13, 18 };

        int[] a = new int[10];
        Scanner sc = new Scanner(System.in);
        System.out.println("Please enter numbers...");
        for (int j = 0; j <= 9; j++) {
            a[j] = sc.nextInt();
        }
        sc.close();

        boolean sumAll = false;

        for (int i : a) {
            for (int j : luckyNumbers) {
                if (i == j) {
                    sumAll = true;
                    break;
                }
            }
            if(sumAll) {
                break;
            }
        }

        if (sumAll) {
            System.out.println("Summing all : " + sumAll(a));
        } else {
            System.out.println("Summing Only Even : " + sumEven(a));
        }

    }

    public static int sumAll(int[] value) {
        int total = 0;
        for (int j : value) {
            total = total + j;
        }
        return total;
    }

    public static int sumEven(int[] value) {

        int total = 0;
        for (int j : value) {
            if (j % 2 == 0) {
                total = total + j;
            }
        }
        return total;
    }

}