Question

Im trying this but doesn’t seem to work:

A  = {{1,2},{3,4}}
A[[1]][[2]] = 5;

How could I do that?

Currently I’m doing

list = {3,5};
A[[2]] = list;

Answer 1

Your code is right, except for a minuscule error 🙂

You wrote:

A = {{1, 2}, {3, 4}}   A[[1]][[2]] = 5; 
                     ^
                     ^
                     |
               This space means
                multiplication!

The correct code is

A = {{1, 2}, {3, 4}} ;  A[[1]][[2]] = 5; 

Usually written as:

    a = {{1, 2}, {3, 4}} ;  
    a[[1, 2]] = 5; 

Remember to start your identifiers with lowercase letters, as capitals are reserved for system’s names