replace array value

I have a matrix

A=[1 2 3; 4 6 6;7 7 7]

I want to replace all 6 in the second column with 12 i.e A should be

as follows: A=[1 2 3; 4 12 12;7 7 7]

How to do that easily?

Answer 1

[Andrei Bobrov]

A(A==6)=12

[Mohammad Golam Kibria]

Actually I need to know replace a particular value of a particular column or row with a specific value. your code replace all values having 6 i.e if

A=[1 2 3; 4 6 6;7 6 7] then output is

A=[1 2 3; 4 12 12;7 12 7]

but output need is:

A=[1 2 3; 4 12 6;7 12 7]

[Oleg Komarov]

A(A(:,2)==6,2) = 12;

[Mohammad Golam Kibria]

Thanks