How to define the number of the column in which a variable corresponds

I have a question about a code. I use the following command in order to read a file:

T=readtable('file.txt')
A=(T:,1);
B=(T:,2);
C=(T:,3);

which command should I use in order to define the number of the column in which a variable corresponds?

for example A coresponts to column 1 (so I want answer=1), B coresponts to column 1 (so I want answer=2), , etc.

Could you please help me?

[Jan]

A and B correspond to 1? I assume this is a typo.

What about:

Aindex = 1;
Bindex = 2;
...

[Ivan Mich]

I would like to export the number 1 (that represents the number of specific column i T table) of command

A=(T:,1)

the number 2 of command

B=(T:,2)

the number 3 of command

C=(T:,3) etc...

Could you please help me?

[Image Analyst]

I did help you. Below in the official Answers section. Did you even see it?

Answer 1

[Image Analyst]

As soon as you assign A, B, and C, you can also create a dictionary so that later in your code you can recall what column they came from

T = randi(9, 5, 3);
A = T(:, 1);
B = T(:, 2);
C = T(:, 3);
dict = dictionary(["A"; "B"; "C"], [1;2;3])

dict = 
  dictionary (string ⟼ double) with 3 entries:

    "A" ⟼ 1
    "B" ⟼ 2
    "C" ⟼ 3

% What column is A from
col = dict("A")

col = 1

% What column is B from
col = dict("B")

col = 2

% What column is C from
col = dict("C")

col = 3