Using loops to populate a vector

Say I have a 3x2 matrix (A) that ranges from the numbers 1 through 5. The 3 rows equals 3 different sets of numbers. I have to use a loop to populate a vector (B) that is the size 3x1 (3 for each set). This vector will populate with the first number in each set (every number in the first column).

So if the matrix A =

2 3 

1 1

5 4

the vector B should be

2

1

5

How would you use the loop function to do that?

Answer 1

[Moe_2015]

If you really need to use a for loop, this is how you could do it.

 for i=1:size(A,1)
    B(i,1)=A(i,1);
  end

However, a more efficient way would be:

B=A(:,1)

[lauuser1]

These both work exactly how I want it, however when I suppress B in the loop function it ceases to show B at all. When I remove the suppression, it shows every step of populating B. This doesn't really affect my code, but would there be a way to fix that?

[Image Analyst]

Fix what? What does suppression mean to you? You mean having the value of B echo to the command window if you leave off the semicolon? If so, I'm still not sure what you want, or don't want, to see.

[lauuser1]

What I am trying to fix is that I just want the final result of B rather than it echoing. I would like to see B in my command window as just one single fully populated 3x1 vector with no values of 0.

[Image Analyst]

Put B by itself after the loop to have it echo only the final B

for i=1:size(A,1)
    B(i,1)=A(i,1); % Semicolon to suppress echo to command window.
end
% Print B to command window:
B