arrays examples in java

Example 1: how to declare an array in java

An array is an ordered collection of elements of the same type, identified by a pair of square brackets []. 
 
 To use an array, you need to:
1. Declare the array with a name and a type. Use a plural name for array, e.g., marks, rows, numbers. All elements of the array belong to the same type.
2. Allocate the array using new operator, or through initialization, e.g.
  
  int[] marks;  // Declare an int array named marks
              // marks contains a special value called null.
int marks[];  // Same as above, but the above syntax recommended
marks = new int[5];   // Allocate 5 elements via the "new" operator
// Declare and allocate a 20-element array in one statement via "new" operator
int[] factors = new int[20];
// Declare, allocate a 6-element array thru initialization
int[] numbers = {11, 22, 33, 44, 55, 66}; // size of array deduced from the number of items

Example 2: array in java

//method 1
int[] age = new int[3];
        age[0] = 1;
        age[1] = 3;
        age[2] = 6;

        for (int i=0; i < 3; i++)
            System.out.println(age[i]);

//method 2
        int[] num = {3,3,5};
        //int num[] = {3,3,5}; also works the same

        System.out.println(num[0]);

Example 3: Arrays in java

// Accessing array elements using for loop
public class AccessingArrayElements
{
   public static void main(String[] args)
   {
      int[] arrNum = {25, 23, 15, 20, 24};
      for(int a = 0; a < arrNum.length; a++)
      {
         System.out.println(arrNum[a]);
      }
   }
}

Example 4: array in java

// datatype var = new datatype[size]

int[] arr = new int[10];
// OR
int arr[] = new int[10];

Example 5: arrays in java

int[] intArray = new int[20];
String[] cars = {"Volvo", "BMW", "Ford", "Mazda"};