Sams Teach Yourself C in 21 Days

In Review 171

144: printf(“\n\nReport totals:”);

CH 07 145: printf(“\nTotal Income is %ld”, grand_total);

146: printf(“\nAverage Income is %ld”, grand_total/ctr );

147:

148: printf(“\n\n* * * End of Report * * *\n”);

149: }

CH 02 150: /*----------------------------------------------------------------*

151: * Function: continue_function() *

152: * Purpose: This function asks the user if they wish to continue.*

153: * Returns: YES - if user wishes to continue *

154: * NO - if user wishes to quit *

155: *----------------------------------------------------------------*/

156:

CH 05 157: int continue_function( void )

158: {

CH 07 159: printf(“\n\nDo you wish to continue? (0=NO/1=YES): “);

160: scanf( “%d”, &x );

161:

CH 06 162: while( x < 0 || x > 1 )

163: {

CH 07 164: printf(“\n%d is invalid!”, x);

165: printf(“\nPlease enter 0 to Quit or 1 to Continue: “);

166: scanf(“%d”, &x);

167: }

CH 04 168: if(x == 0)

CH 05 169: return(NO);

CH 04 170: else

CH 05 171: return(YES);

172: }

LISTINGR1.1 continued

After completing the quizzes and exercises on Day 1, “Getting Started with C,”

and Day 2, “The Components of a C Program,” you should be able to enter and

compile this program. This program contains more comments than any other listing

throughout this book. These comments are typical of a “real-world” C program. In par-

ticular, you should notice the comments at the beginning of the program and before each

major function. The comments on lines 1 to 5 give an overview of the entire program,

including the program name. Some programmers also include information such as the

author of the program, the compiler used, its version number, the libraries linked into the

program, and the date on which the program was created. The comments before each

function describe the purpose of the function, possible return values, the function’s call-

ing conventions, and anything relating specifically to that function.

The comments on lines 1 to 5 specify that you can enter information in this program for

up to 100 people. Before you can enter the data, the program calls display_instruc-

tions()on line 45. This function displays instructions for using the program and asks

ANALYSIS

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