Making a list from two arrays

I'm relatively new to coding, and have no clue how I would pull the following off.

Say I have two vectors: A = [a b c d] and B = [1 2 3 4].

I would like to make a function that takes these two as inputs and outputs exactly the following into a .txt file, curly brackets included:

{a->1,b->2,c->3,d->4}

I was thinking some kind of for loop, but I have no experience using them and no idea how I would set this up.

Thanks

Answer 1

[Azzi Abdelmalek]

A = {'a' 'b' 'c' 'd'} 
B = [1 2 3 4]
out='{'
for k=1:numel(B)
  out=[out sprintf('%s->%d,',A{k},B(k))]
end
out(end)='}'

%or

A = {'a' 'b' 'c' 'd'} 
B = [1 2 3 4]
out=['{' strjoin(cellfun(@(x,y)  sprintf('%s->%d',x,y),A,num2cell(B),'un',0),',') '}']

[Julien]

Thanks, this works exactly as I wanted it to.

Answer 2

[Evan]

How about this?

A = 'abcd';
B = [1 2 3 4];
fid = fopen('my_txt_file','w');
s = [];
for i = 1:numel(A)
   s = [s sprintf('%s->%d,',A(i),B(i))];
end

s = ['{' s(1:end-1) '}'];
fprintf(fid,s);
fclose(fid)