Sams Teach Yourself C in 21 Days

12:

13: char *just_for_fun = “Just For Fun!!!”;

14:

15: cout << “\n\njust_for_fun = “ << just_for_fun << “\n”;

16:

17: return 0;

18: }

Line: 1 - printing the char: x

Line: 2 - printing the char: x

Line: 3 - printing the char: x

Line: 4 - printing the char: x

Line: 5 - printing the char: x

Line: 6 - printing the char: x

Line: 7 - printing the char: x

Line: 8 - printing the char: x

Line: 9 - printing the char: x

just_for_fun = Just For Fun!!!

As you can see, this is a pretty straightforward listing. Line 8, where the ctr

variable is being declared, should be of particular interest. In a pure C program,

this listing would generate an error. In C, you would be required to declare ctrearlier, at

the beginning of the function. Declaring a variable at the beginning of a looping struc-

ture, as shown in Listing B2.4, is very common in C++. In C++, you can declare a vari-

able when you are ready to use it.

As a second example, line 13 also declares a variable,just_for_fun. This is obviously

not at the beginning of a block, nor is it at the beginning of the main()function. As you

can see, this variable is perfectly valid in C++ and prints its contents using the cout

object in the next line.

Be careful about declaring variables in the middle of a function. Although C++ allows

you to declare variables anywhere, if declare your variables at the beginning of a block,

you make it easier for others to find and understand them. This, in turn makes it easier to

debug the program.

654 Bonus Day 2

LISTINGB2.4 continued

OUTPUT

ANALYSIS

DOdeclare variables at the beginning of

blocks rather than in the middle in order

to make your programs easier to follow.

DON’Tforget that local variables take

precedence over global variables if the

same name is used.

DO DON’T

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