Objects difference between javascript and C#

I want to convert a code from JavaScript to C#. in javascript we can use an object easily as follows, this function returns the indices of the elements that their addition is equal to the target

const nums = [1, 5, 6, 7, 10];
const target = 12;
var twoSum = function(nums, target) {
    let obj = {};
    for (i=0;i<nums.length;i++){
        let found = target-nums[i];
        if(obj[found] != null){
            return [obj[found], i]
        }else{
            obj[nums[i]] = i;
        }
    }
}

the return of the function will be [1,3] which is an array of the indices of 5,7 (as 5+7 = 12)

So what is a similar way to accomplish this solution in c#? Is this applicable by using Objects in C#? or even Arrays/Lists/Dictionaries? What is the best way?

Thanks

Answer

You can do that in JavaScript because arrays are secretly objects here.

In C# it will be a little more complicated because you can’t enlarge arrays like that.

You can use List, but you will have to increase the length and insert nulls in between.

I suggest using a dictionary because it’s similar to JavaScript’s object.

var nums = new Dictionary<int, int>()  {
  { 0, 1 },
  { 1, 5 },
  { 2, 6 },
  { 3, 7 },
  { 4, 10 }
}

Then you can iterate like that:

foreach(KeyValuePair<int, int> entry in nums)
{
    // do something with entry.Value or entry.Key
}