Page 65 - DCAP201_FUNDAMENTALS_OF_DATA_STRUCTURES

Fundamentals of Data Structures Kumar Vishal, Lovely Professional University

Notes Unit 5: Pointers

CONTENTS
Objectives
Introduction

5.1 Concept of Pointers
5.1.1 Pointer and Functions
5.1.2 Pointers and Arrays

5.2 Arrays of Pointers
5.2.1 Multidimensional Arrays and Pointers
5.2.2 Static Initialisation of Pointer Arrays
5.3 Records and Record Structures
5.3.1 Indexing Items in a Record

5.3.2 Representation of Records in Memory; Parallel Arrays
5.4 Summary
5.5 Keywords

5.6 Review Questions
5.7 Further Readings

Objectives

After studying this unit, you will be able to:

Discuss the concept of pointers
Explain array of pointers
Discuss records and record structures
Explain representation of records in memory, parallel arrays

Introduction

A pointer is nothing but a variable that contains an address of a location in memory. Pointers are
used everywhere in C, and if you have a good understanding of them C should not pose a
problem. C pointers are basically the same as Pascal pointers except they are used much more
freely in C. A pointer is a variable that points to another variable. This means that it holds the
memory address of another variable. Put another way, the pointer does not hold a value in the
traditional sense; instead, it holds the address of another variable. It points to that other variable
by holding its address. Because a pointer holds an address rather than a value, it has two parts.
The pointer itself holds the address. That address points to a value. There is the pointer and the
value pointed to. This fact can be a little confusing until you get used to it. In this unit, we will
discuss the concept of pointers and array of pointers. We will also discuss the concept of record
and record structures.

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