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CHAPTER 10: DATA TYPES AND STRUCTURES

10.1 DATA TYPES

10.1.1 Primitive Data Types

Type Description
INTEGER Whole numbers
REAL Decimal numbers
CHAR Single character
STRING Sequence of characters
BOOLEAN True/False
DATE Date values

10.1.2 Records

Definition: A structure that holds a set of data of different types under one identifier.

Purpose:

Example:

<TEXT>

RECORD Employee
DECLARE EmpID : INTEGER
DECLARE Name : STRING
DECLARE Salary : REAL
END RECORD

10.2 ARRAYS

10.2.1 One-Dimensional Arrays

Definition: A collection of elements of the same type accessed by index.

Terms:

  • Index: Position of element
  • Lower bound: First index (usually 0 or 1)
  • Upper bound: Last index

Declaration:

<TEXT>

DECLARE arrayname[upperbound] : TYPE

Access:

<TEXT>

arrayname[index]

10.2.2 Two-Dimensional Arrays

Definition: Array of arrays; elements accessed by row and column.

Declaration:

<TEXT>

DECLARE arrayname[row, column] : TYPE

10.2.3 Array Operations

Linear Search:

  • Check each element sequentially
  • Works on unsorted data
  • O(n) time complexity

Bubble Sort:

  • Compare adjacent elements
  • Swap if in wrong order
  • Repeat until sorted
  • O(n²) time complexity

10.3 FILES

10.3.1 File Need

  • Store data permanently
  • Large amounts of data
  • Data persistence between program runs

10.3.2 File Operations

Opening:

<TEXT>

OPENFILE filename FOR READ/WRITE/APPEND

Reading:

<TEXT>

READFILE filename, variable

Writing:

<TEXT>

WRITEFILE filename, variable

Closing:

<TEXT>

CLOSEFILE filename

10.4 ABSTRACT DATA TYPES (ADT)

10.4.1 Stack

Characteristics:

  • LIFO (Last In, First Out)
  • Add to top (push)
  • Remove from top (pop)

Operations:

  • Push: Add item to top
  • Pop: Remove item from top
  • Peek: View top item without removing

10.4.2 Queue

Characteristics:

  • FIFO (First In, First Out)
  • Add to rear (enqueue)
  • Remove from front (dequeue)

10.4.3 Linked List

Characteristics:

  • Dynamic structure
  • Nodes contain data and pointer to next node
  • Can grow/shrink easily

Operations:

  • Add node
  • Delete node
  • Search
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