Presentation is loading. Please wait.

Presentation is loading. Please wait.

Pointers Lecture 1 Thu, Jan 15, 2004.

Published bySri Halim Modified over 6 years ago

Similar presentations

Presentation on theme: "Pointers Lecture 1 Thu, Jan 15, 2004."— Presentation transcript:

1 Pointers Lecture 1 Thu, Jan 15, 2004

2 Topics Pointers Declaring Pointers Null Pointers The Address Operator
Dereferencing Pointers Pointers to Void Assignment of Pointers 2/22/2019 Pointers

3 Pointers A pointer is an object that refers to another object.
A pointer holds the address of the object that it refers to. All pointers occupy 4 bytes of memory. 2/22/2019 Pointers

4 Declaring Pointers Write the type of object that the pointer points to, followed by *, followed by the pointer name. int* pi; float* pf; 2/22/2019 Pointers

5 Null Pointers A null pointer is a pointer that has the value zero.
A null pointer does not point to any object. The constant NULL has the value 0. It is a good practice to initialize a pointer to NULL. int* pi = NULL; 2/22/2019 Pointers

6 The Address Operator The unary prefix operator & returns the address of an object. The address may be assigned to a pointer. Example: AddressOperator.cpp int i; int* pi = &i; // &i is address of i 2/22/2019 Pointers

7 Dereferencing Pointers
When a pointer is dereferenced, it returns the object that it points to. The unary pre-fix operator * is used to dereference a pointer. Never dereference a null pointer. Example: DereferencePointers.cpp int i = 10; int* pi = &i; // pi points to i cout << *pi << endl; // Print i 2/22/2019 Pointers

8 Pointers to void A pointer to void (void* object) is a pointer that does not point to any particular kind of object. (void “objects” do not exist.) void is treated as a “neutral” type for situations where the type does not matter. A void pointer may hold the address of any object. A void pointer may not be dereferenced. 2/22/2019 Pointers

9 Assignment of Pointers
The pointer assignment p1 = p2 is legal if and only if p1 and p2 point to the same type of object, or p1 is a pointer to void. Otherwise, cast p2 to be compatible with p1. Assigning pointers to different types can cause serious problems. 2/22/2019 Pointers

10 Example: Pointer Assignment
Example: PtrCompatibility.cpp void* pv; int* pi; float* pf; pv = pi; pi = (int*)pf; pf = (float*)pv; 2/22/2019 Pointers

Download ppt "Pointers Lecture 1 Thu, Jan 15, 2004."

Similar presentations

Chapter 9 Pointers and Dynamic Arrays. Overview 9.1 Pointers 9.2 Dynamic Arrays.

Chapter 9 Pointers and Dynamic Arrays. Overview 9.1 Pointers 9.2 Dynamic Arrays.
A pointer is the memory address of a variable. A memory address is a physical location within a system’s memory space. A pointer variable is variable used.

A pointer is the memory address of a variable. A memory address is a physical location within a system’s memory space. A pointer variable is variable used.
Data Structures (Second Part) Lecture 2 : Pointers Bong-Soo Sohn Assistant Professor School of Computer Science and Engineering Chung-Ang University.

Data Structures (Second Part) Lecture 2 : Pointers Bong-Soo Sohn Assistant Professor School of Computer Science and Engineering Chung-Ang University.
© Janice Regan, CMPT 128, February. 2007 0 CMPT 128: Introduction to Computing Science for Engineering Students Pointers.

© Janice Regan, CMPT 128, February CMPT 128: Introduction to Computing Science for Engineering Students Pointers.
This Time Pointers (declaration and operations) Passing Pointers to Functions Const Pointers Bubble Sort Using Pass-by-Reference Pointer Arithmetic Arrays.

This Time Pointers (declaration and operations) Passing Pointers to Functions Const Pointers Bubble Sort Using Pass-by-Reference Pointer Arithmetic Arrays.
1 Pointers A pointer variable holds an address We may add or subtract an integer to get a different address. Adding an integer k to a pointer p with base.

1 Pointers A pointer variable holds an address We may add or subtract an integer to get a different address. Adding an integer k to a pointer p with base.
1 CSE1301 Computer Programming Lecture 16 Pointers.

1 CSE1301 Computer Programming Lecture 16 Pointers.
Pointers and References (1) THE REFERENCE OPERATOR REFERENCES POINTERS THE DEREFERENCE OPERATOR DERIVED TYPES RETURNING A REFERENCE.

Pointers and References (1) THE REFERENCE OPERATOR REFERENCES POINTERS THE DEREFERENCE OPERATOR DERIVED TYPES RETURNING A REFERENCE.
Pointers. Topics Pointers Pointer Arithmetic Pointers and Arrays.

Pointers. Topics Pointers Pointer Arithmetic Pointers and Arrays.
1 Pointers, Dynamic Data, and Reference Types Review on Pointers Reference Variables Dynamic Memory Allocation –The new operator –The delete operator –Dynamic.

1 Pointers, Dynamic Data, and Reference Types Review on Pointers Reference Variables Dynamic Memory Allocation –The new operator –The delete operator –Dynamic.
1 Chapter 9 Pointers. 2 Topics 8.1 Getting the Address of a Variable 8.2 Pointer Variables 8.3 Relationship Between Arrays and Pointers 8.4 Pointer Arithmetic.

1 Chapter 9 Pointers. 2 Topics 8.1 Getting the Address of a Variable 8.2 Pointer Variables 8.3 Relationship Between Arrays and Pointers 8.4 Pointer Arithmetic.
Programming Pointers. COMP104 Lecture 32 / Slide 2 Pointers l Pointers are objects whose values are the locations of other objects l Pointers are memory.

Programming Pointers. COMP104 Lecture 32 / Slide 2 Pointers l Pointers are objects whose values are the locations of other objects l Pointers are memory.
1 CSE1301 Computer Programming Lecture 16 Pointers.

1 CSE1301 Computer Programming Lecture 16 Pointers.
1 Procedural Concept The main program coordinates calls to procedures and hands over appropriate data as parameters.

1 Procedural Concept The main program coordinates calls to procedures and hands over appropriate data as parameters.
C++ Data Types Structured array struct union class Address pointer reference Simple IntegralFloating char short int long enum float double long double.

C++ Data Types Structured array struct union class Address pointer reference Simple IntegralFloating char short int long enum float double long double.
Chapter 9 Pointers and Dynamic Arrays (9.1). Pointers A variables which holds the memory address for a variable of a specific type. Call-by-Reference.

Chapter 9 Pointers and Dynamic Arrays (9.1). Pointers A variables which holds the memory address for a variable of a specific type. Call-by-Reference.
Dynamically Allocated Arrays December 4, 2013. Skip the Rest of this PowerPoint.

Dynamically Allocated Arrays December 4, Skip the Rest of this PowerPoint.
Pointers. What is pointer l Everything stored in a computer program has a memory address. This is especially true of variables. char c=‘y’; int i=2; According.

Pointers. What is pointer l Everything stored in a computer program has a memory address. This is especially true of variables. char c=‘y’; int i=2; According.
Copyright 2005, The Ohio State University 1 Pointers, Dynamic Data, and Reference Types Review on Pointers Reference Variables Dynamic Memory Allocation.

Copyright 2005, The Ohio State University 1 Pointers, Dynamic Data, and Reference Types Review on Pointers Reference Variables Dynamic Memory Allocation.
Tracing through E01, question 9 – step 1 // p02.cc P. Conrad, for CISC181 07S // Exam question for E01 #include using namespace std; void mysteryFunction(int.

Tracing through E01, question 9 – step 1 // p02.cc P. Conrad, for CISC181 07S // Exam question for E01 #include using namespace std; void mysteryFunction(int.

Similar presentations

Ads by Google