Java: Array with loop

Question

I need to create an array with 100 numbers (1-100) and then calculate how much it all will be (1+2+3+4+..+100 = sum).

I don\'t want to enter these numbers into the a

Answer 1

this is actually the summation of an arithmatic progression with common difference as 1. So this is a special case of sum of natural numbers. Its easy can be done with a single line of code.

int i = 100;
// Implement the fomrulae n*(n+1)/2
int sum = (i*(i+1))/2;
System.out.println(sum);

Answer 2

I'm not sure what structure you want your resulting array in, but the following code will do what I think you're asking for:

int sum = 0;
int[] results = new int[100];
for (int i = 0; i < 100; i++) {
  sum += (i+1);
  results[i] = sum;
}

Gives you an array of the sum at each point in the loop [1, 3, 6, 10...]

Answer 3

int[] nums = new int[100];

int sum = 0;

// Fill it with numbers using a for-loop for (int i = 0; i < nums.length; i++)

{ 
     nums[i] = i + 1;
    sum += n;
}

System.out.println(sum);