Question

All columns in a matrix must have the same mode and the _________ length.

(a) Different

(b) Same

(c) May be the same

(d) May be different

The question was asked in an internship interview.

My query is from Data Types topic in chapter Nuts and Bolts and Getting Data In and Out of R Programming

Answer 1

Correct option is (b) Same

Easiest explanation: All columns in a matrix must have the same mode(numeric, character, etc) and also the same length. byrow=TRUE indicates that the matrix should be filled by rows. byrow=FALSE indicates that the matrix should be filled by columns (the default).