CMSC 202 Computer Science II, Spring 2016, Section 01

Lecture 14: Example: 2D Arrays

Tue 03/22, 2016

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Assigned Reading: 

Slides As Shown:

• Announcements, etc: [slide view] [print view]

• Hack : [slide view] [print view]

• 2D arrays: [slide view] [print view]

Topics Covered:

Project 3 released.

"Hacking" around const and private using void * pointers:

• ahack1.cpp shows a const member function changing a data member. shows a const member function changing a data member.
• ahack1a.cpp shows a main function that alters a private data member.
• Discussion of a perhaps more straightforward implementation of a two dimensional array. (See slides.)

  In the first implementation, we used a member function at() to access items in the 2D array. The [] operator also works, but doesn't check bounds: twodim.h, twodim.cpp, tdtest.cpp.

  In the second implementation, we made the [] operator check bounds, but we had to define a small class SmartIntPtr just to check the column number is in bounds: twodim2.h, twodim2.cpp, tdtest2.cpp.