Arrays

Our first look at structured data.
Simple types: int, char, float, bool.
Composite types: more complex arrangements of simple types.
Recall assignment 7 with 3 scores

 float score1, score2, score3;       //to declare
 ... 
 cin >> score1 >> score2 >> score3   //to read
 ... 
 sum = score1 + score2 + score3      //to add
 ...
 cout << score1 << score2 << score3  //to read
 ...
 ???                                 //put in increasing order

What if there were 5 scores? 10?
We need a way to handle pieces of related data.

Arrays: a structured data type consisting of a collection of memory cells for storing a list of values that are all the same type.

Later, records: a data structure for storing related elements of different types.
Examples:

Sayings at the bottom of the page
Sudoku

Declaration:
int score[5];

[ ]

0 1 2 3 4

To access the elements:

score[3] = 7;
cout << score[2];

Out of bound indices:

score[5]= 8: // uses the next space

Arrays as paramters:

Passing by value would require copying over the entire array.
Too expensive.
Default: arrays are passed by reference.
Therefore omit the &.

13.2 Shortcomings of Arrays

1. No range checking
2. No good way to dynamically resize an array
3. Inconsistent syntax

One approach to handle this: a built-in class called vector (Sections 13.3-13.8).
We will not follow this. See class examples for alternate material.

Comment: an array subscript cannot be a character.