10.1 Data types and records

INTEGER, REAL, CHAR, STRING, BOOLEAN, DATE, ARRAY, FILE

Record structure

• A set of related data items

• Can be different data types

Read data from a record structure

Save data to a record structure

10.2 Arrays

• A data structure in a program that uses the same identifier name for several data values

• Used for a collection of items of the same data type

10.3 Files

OPENFILE "File1.txt" FOR WRITE
WRITEFILE "File1.txt", EmployeeString
CLOSEFILE "File1.txt"

Write mode is for new files

Append mode is to add a line of text to the end of the existing file

10.4 Introduction to Abstract Data Types (ADT)

ADT is a collection of data and a set of operations on those data

Understanding that a stack, queue and linked list are examples of ADT

Stack

• Last item added will be the first to leave

Queue

• First item added will be the first to leave

Linked list

• A data structure consisting of a set of nodes

• Each node consists of the data value and a link pointer to one of the other nodes

• The purpose is to link the nodes in some particular order

Use them to store data

Describe how a queue, stack and linked list can be implemented using arrays

Stack

• Store the values in an array: lower bound 1 and upper bound N

• A pointer indicates the position of the item that is currently at the top of the stack

Queue

• Store the values in an array: lower bound 1 and upper bound N

• The queue is controlled by two pointers, a head pointer which points to the item that is currently at the head of the queue, a tail pointer points to the item that is currently at the rear of the queue

• A new item is always added to the end of the queue

Linked list

• Store the data using two 1D arrays

• First array for the data values

• Second array for the link pointers

• A start pointer is needed, which is the array index of the first item in the list

• A next free position index pointer is needed to show where the next new value is stored