1. THE C PROGRAM WORKSHOP

2. Workshop Features Door for expected results to go out Door for requests to go in Door for unexpected results to go out Bins for parts and supplies Various tools WORKSHOP XYZ ABCD Instructions and operating procedures Communication with other shops

3. A computer program written in C is like a workshop It brings data into the program from the outside world, performs some processing with it, makes some changes to it, and then returns it to the outside world in a different form main Current Data (Information) Transformed Data (Information)

4. C Program Entrances and Exits STANDARD OUT (stdout) STANDARD IN (stdin) STANDARD ERROR (stderr) Constants and variables Operations and functions main XYZ ABCD Instructions and operating procedures File and Device Input/Output

5. Data Types Integers (int) Numbers with decimal points (float) Characters (char) Words and Phrases (ex. char phrase[10]) Tables (ex. int values[10], float matrix[20][30]) Records (ex. struct myRecordType)

6. Data Storage Locations int aNumber; float aValue; char aSymbol; char phrase[LENGTH]; int values[15];

7. Simple Operations Storage ( = ) Addition ( + ) Subtraction ( - ) Multiplication ( * ) Division ( / ) Modulo ( % ) Comparison ( ==, !=,, >= )

8. Instructions and Decisions variableLocation = expression –Ex. count = 17 * MAX_LOOPS; if (Boolean condition) statement else statement –Ex. if (numberIsValid) count++; else count--; while (Boolean condition) statement –Ex. while (count > MAX_LOOPS) count = count – 5; for (statement; condition; statement) statement –Ex. for (i = 0; i < size; i++) printf(“%d\n”, table[i]);

9. Technical Vocabulary: C Keywords autodoubleintstruct breakelselongswitch caseenumregistertypedef charexternreturnunion constfloatshortunsigned continueforsignedvoid defaultgotosizeofvolatile doifstaticwhile (Note: Keywords in bold-face font are used with data types)

10. Standard C Library Functions Standard Input and Output: –printf, scanf, getchar, gets Conversion of Data: –isalpha, isdigit, tolower, toupper Math: –sin, cos, tan, sqrt, log, exp Working with Files: –fopen, fclose, fscanf, fprintf, fgets

11. Example Program - C Source Code int main(void) { int theCheckNbr; char theAccount; char theTaxCode; float theAmount; float theBalance; theBalance = 2391.52; printf("Ck Nbr Acct Tax Amount Balance\n"); printf("------ ---- --- ------ -------\n"); theCheckNbr = 234; theAccount = ‘B'; theTaxCode = ‘Z'; theAmount = 34.56; theBalance = theBalance - theAmount; printf("%6d %2c %2c %6.2f %7.2f\n", theCheckNbr, theAccount, theTaxCode, theAmount, theBalance); return 0; } // End main

12. Example Program Output Ck Nbr Acct Tax Amount Balance ------ ---- --- ------ ------- 234 A Z 34.56 2356.96

13. Example Program Exercise Using the current pattern of statements in the program, add the source code to display the last two lines of the report shown below Also, change the order of the report columns Ck Nbr Amount Acct Balance Tax ------ ------ ---- ------- --- 234 34.56 B 2356.96 Z 235 192.73 T 2164.23 W 236 75.00 G 2089.23 X