Given an array of integers, print the sum of all the elements in an array.
Examples:
Input: arr[] = {1,2,3,4,5}
Output: 15
Input: arr[] = {2, 9, -10, -1, 5, -12}
Output: -7
Approach 1: Iteration in an Array
- Create a variable named sum and initialize it to 0.
- Traverse the array through a loop and add the value of each element into sum.
- Print sum as the answer.
Below is the implementation of the above approach.
Java
// Java Program to print the sum // of all the elements in an arrayclass GFG {      static int sumOfArray(int arr[])    {        // initialise sum to 0        int sum = 0;                // iterate through the array using loop        for (int i = 0; i < arr.length; i++) {            sum = sum + arr[i];        }          // return sum as the answer        return sum;    }      // Driver code    public static void main(String[] args)    {        // print the sum        int arr[] = { 1, 2, 3, 4, -2, 5 };        System.out.println(            "The sum of elements of given array is: "            + sumOfArray(arr));    }} |
Output
The sum of elements of given array is: 13
Time Complexity: O(N), where N is the size of array
Approach 2: IntStream.of(arrayName).sum()
Inbuilt function IntStream.of(arrayName).sum() is used to sum all the elements in an integer array.
Syntax:
IntStream.of(arrayName).sum();
Below is the implementation of the above approach.
Java
// Java Program to print the sum // of all the elements in an array  // import IntStreamimport java.util.stream.IntStream;  class GFG {      // Driver code    public static void main(String[] args)    {        // print the sum        int arr[] = { 1, 2, 3, 4, -2, 5 };        System.out.println(            "The sum of elements of given array is: "            + IntStream.of(arr).sum());    }} |
Output
The sum of elements of given array is: 13
