Question about searching a number in file suffix

I have a question about a command I would like to use. I have several files with multiple suffixes, for example file_1.txt, file_2.txt, file_3.txt etc.

I would like to read a specific file depending on a value of a variable. For example if my value is equal to 4 I would like to read file file_4.txt. if my value is equal to 5 I would like to read file file_5.txt.

Which command should I use in order to make it?

Coule you please help me?

Answer 1

[Dyuman Joshi]

d=5;
s=sprintf('file_%d.txt',d)

s = 'file_5.txt'

%command for reading the file
fileread(s)