Laboratory 5: Pointers and String

An object variable contains an object, but a pointer specifies where an object is located. 
In C++, pointers are important for several reasons. 
Pointers can refer to objects that are dynamically allocated whenever they are needed.
Pointers can be used for shared access to objects. 
Furthermore, as you will see, pointers are necessary for implementing polymorphism, 
an  important concept in object-oriented programming.
In C++, there is a deep relationship between pointers and arrays. You will see how this relationship
explains a number of special properties and limitations of arrays.
Finally, you will see how to convert between string objects and char* pointers, which is necessary when
interfacing with legacy code.

Goals:

1. To learn how to declare, initialize, and use pointers
2. To become familiar with dynamic memory allocation and de-allocation
3. To use pointers in common programming situations that involve optional and shares objects
4. To avoid the common errors of dangling pointers and memory leaks
5. To understand the relationship between arrays and pointers
6. To be able to convert between string objects and character pointers

• Powerful
• but difficult to master
• Simulate pass-by-reference
• Close relationship with arrays and strings

• Notes

• Codes

  1. Pointer operators (read 5.3)
  Example 1
  Fig05_04.cpp
  Explain the output 
       
  Example 2 
  pointers.cpp  
  (Unix Makfile pointers.make)
  Explain the output, Draw the identifiers and their values as they are arranged in memory . 
   
  2. Calling functions by reference (read 5.4)    
  Example 3
  Fig05_06.cpp
  
  Example 4
  Fig05_07.cpp
  
  3. Using const with pointers (read 5.5)    
  Example 5
  Fig05_10.cpp
  
  Example 6
  Fig05_11.cpp

  Example 7
  Fig05_12.cpp
  
  Example 8
  Fig05_13.cpp
  
  Example 9  (bubble sort)
  Fig05_15.cpp
  
  4. Relationship between Pointers and Arrays  (read 5.8, 5.9)    
  Example 10
  Fig05_20.cpp
  
  Example 11  (Arrays of Pointers)
  Fig05_21.cpp
   
  5. Function Pointers (read 5.11)    
  Example 12
  Fig05_26.cpp
  
  6. Relationship between Pointers and Arrays  (read 5.12)    
  
  
  Example 14
  Fig05_28.cpp
  
  Example 15 
  Fig05_30.cpp
  
  Example 16 
  Fig05_31.cpp
  
  Example 17 
  Fig05_32.cpp
  
  Exercise A2Q3, A2Q4
  practice.cpp