Sorting numbers according to elements of an array

Sorry for the vague title, I asked a similar question earlier very poorly and I extracted the most fundamental concept that I am trying to wrap my head around and I hope I will be articulate enough this time.

I want to sort elements accordingly;

I have 3 elements in my SORTING array, 3, 7 and 11

My input is 4.1, since this is closest to 3, the output will be equal to 3. Looking at it, it seems intuitive but I am struggling on how to break this down to explain it to MATLAB

In reality I am working with numbers sensitive to the 4th decimal place, but I am trying to understand the concept behind this sorting method

SORTING = [3 7 11]';
input = 4.1;
%code to compute which number it is closest to
output = 3;
%further calulcations based on output

Answer 1

[KSSV]

SORTING = [3 7 11]';
input = 4.1;
%code to compute which number it is closest to
% output = 3;
% GEt the absolute difference with given input and it's minimum 
[val,idx] = min(abs(SORTING-input)) ;
output = SORTING(idx)

Answer 2

[per isakson]

Without comment:

>> [~,ix]=min(abs(SORTING-input))
ix =
     1
>> SORTING(ix)
ans =
     3
>> 
>> [~,ix]=min(abs(SORTING-12))
ix =
     3
>> SORTING(ix)
ans =
    11