sum of array past user input

Question

hi guys new to programming and to stack overflow. I was wondering if i could get a few pointers, so basically i've made an array holding values of 1-200. But now i would like to be able to ask the user for input and then add together the remaining numbers in the array.

e.g. user enters 100 - so then all numbers from 100 - 200 are added together and then the total outputted.

I have a feeling it will be something really simple I just don't know where to start.

Thanks Guys.

Possible duplicate : http://stackoverflow.com/questions/2622725/how-to-take-user-input-in-array-using-java — Shiladittya Chakraborty, Jan 20 '16 at 12:46
https://docs.oracle.com/javase/tutorial/java/nutsandbolts/for.html — sinclair, Jan 20 '16 at 12:47

score 3 · Answer 1 · answered Jan 20 '16 at 12:48

3

I just don't know where to start.

Write a HelloWorld programm to learn how to output something.
Write a program which reads some input values, in different datatypes.
Learn how for-loops work.
Put all your knowledge together.

answered Jan 20 '16 at 12:48

kai

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Marcx · Answer 2 · 2016-01-20T17:14:28.677

You can use a the Scanner s = new Scanner(System.in); to ask an input from the user...

Then simply use a for loop starting from the inputted value to the end of the array and sum the results..

int sum = 0;
for (int i = inputtedValue ; i < 200 ; i++)
{
   sum += array[i];
}

System.out.println(sum);

EDIT

For better understanding for the OP I am editing my answer posting the complete code, although it is not how stackoverflow works.

public static void main(String [] args)
{
    Scanner s = new Scanner(System.in);
    int inputtedValue = s.nextInt();
    s.nextLine();
    int[] array = new int[200];
    for (int i = 0 ; i < 200 ; i++)
    {
       array[i] = i+1;
    }

    int sum = 0;
    for (int i = inputtedValue ; i < 200 ; i++)
    {
       sum += array[i];
    }

    System.out.println(sum);
}

input: 199 output: 200

input: 100 output: 15050

input: 0 output: 20100

Thank you for your quick reply. i have used to above code which you suggested and it now makes sense to me :) but the sum is outputting at 0 every time. have i done something wrong? — bigbeans, Jan 20 '16 at 13:36
I edited my answer with the full code... how this helps you understanding how it works. — Marcx, Jan 20 '16 at 17:14

sum of array past user input

2 Answers2