I’m looking to decode an existing switch matrix (4 Rows and 16 Columns, basically copy the states of the Rows and Columns).
The goal is to ultimately have a [data] where I will have:
ROW 1 == LOW && COL 1 == LOW, which will result in DATA == LOW.
In my case, only INPUTs are needed, the Arduino should not generate the matrix but only read it (so no OUTPUTs).
After obtaining this variable [DATA], I need to add a condition Supp [DATA] && x == 1 to store it in another variable in order to pass it into a SWITCH CASE.
Then, I can do things like: (but I have 64 switches)

if (ROW 1 == LOW && COL 1 == LOW) {  
  // for example, turn a LED to HIGH  
}  
else {  
  // if necessary  
}