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This chapter explores the use of pointers in computer programming in the field of Earth Sciences. Topics covered include the concept of pointers, accessing class member data and functions, managing data on the free store, and memory leaks. Learn how pointers can be used to manipulate data and improve programming efficiency in this specialized domain.
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Chapter 8 Pointers Applications of Computer Programming in Earth Sciences Instructor: Dr. Cheng-Chien Liu Department of Earth Sciences National Cheng Kung University Last updated: 2 November 2004
Introduction • Pointer • A variable that holds a memory address • Ex 8-1 • “Address of” operator & • Convention of naming • Declaration • Indirection (dereference) operator * • 提領(取出指標所指物體的內容) • The value stored at … • Initialization • Wild pointer dangerous • Pointers addresses variables • Manipulating data: Ex 8-2 • Examining the address: Ex 8-3
Why use pointers • Three tasks of using pointers • Managing data on the free store • Accessing class member data and functions • Passing variables by reference to functions • Five areas of memory • Global name space global variables • The free store heap all remaining memory • Registers internal housekeeping • Code space code • The stack local variables, function parameters • Concept of free store
Using free store • Advantages of free store • Solves the problem of global and local variable • Remains available until you explicitly free it • Only functions with access to the pointer tightly controlled interface • How to use the free store • new • delete • Ex 8-4 • Ex 8-5: applying to object • Memory leak
Using free store (cont.) • Access member data of objects • dot operator “.” • points-to operator “->” • Ex 8-6 • Ex 8-7 • Stray pointers • Ex 8-9 • const pointers • Ex 8-10