//BASIC ARRAY CONCEPTS

//Declare an array and then allocate memory
int myArray[];
myArray = new int[4];

//Declare while directly assign values
int[] myArray1 = new int[]{ 1, 6, 7, 9};

//Initialize element
myArray[0] = 2;

//Create an array of objects
Object[] arr = new Object[5];

//Basic for loop to print elements of array
int[] arr1 = {0, 6, 8, 2};

// Looping through array by incrementing value of i
//'i' is an index of array 'arr1'
for (int i = 0; i < arr1.length; i++) {

    // Print array element present at index i
    System.out.println(i + " " + arr1[i]);

}

// NOTE: You may also use an enhanced for loop

for(int value: arr1){
    System.out.println(value);
}

0 0
1 6
2 8
3 2
0
6
8
2

Hack 1

void setArray(int[] arr, int n) {
    for (int i = 0; i<array.length; i++) {
        arr[i] = n;
    }
}

int[] array = new int[10];
setArray(array, 10);

for (int i = 0; i<array.length; i++) {
    System.out.println(array[i]);
}

// Should print all 10s when working properly

10
10
10
10
10
10
10
10
10
10

Hack 2

//Example finding the max in an array. 

//Finds the maximum in an array
public static float average(int[] array) {
    float sum = 0;
    for (int element : array) {
        sum += element;
    }
    return sum/array.length;
}

//tester array
int[] test = {3, 5, 7, 2, 10};

//returns 10
System.out.println(average(test));

5.4

Hack 3

public static float averageDiagonal (int[][] array2D) {
    int sum = 0;
    int count = 0;
    for (int i = 0; i < array2D.length; i++) {
        try {
            sum += array2D[i][i];
            count++;
        } catch(Exception e) {
        }
    }
    return (float) sum/count;
}

int[][] arr = {
    {1,2,3,4,5,6},
    {7,8,9,10,11,12},
    {0,1,2,3,4,5},
    {10,11,12,13,14,15},
    {15,16,17,18,19,20}
};

System.out.println(averageDiagonal(arr));

8.6