121 Week 7 - 2D Arrays

Question 1

2D array

Answer 1

An array where each element in the array is another array.
Created in C by: datatype arrayName[int][int];

Question 2

Indexing a 2D array

Answer 2

You can access individual elements in a 2D array using 2 sets of square brackets. The first for the “row” and the second for the “column”
e.g., arrayName[2][3]

Question 3

Pros of 2D arrays

Answer 3

Can use a single name to represent multiple data items of the same type.
Random access so very fast to access an individual item.

Question 4

Cons of 2D arrays

Answer 4

Arrays are fixed sizes
Insertion and deletion from arrays are costly

Question 5

Constants

Answer 5

Similar to a variable but once it is defined, its value cannot be changed - it is kept constant. constant names are conventionally in uppercase.
#define CONST_NAME value

Question 6

Benefits of constants

Answer 6

Can use the constant to represent a value which can be used throughout the code. If this value needs to be different, only change 1 line of code - the constant definition.