Massachusetts Institute of Technology
Department of Electrical Engineering and Computer Science
6.087: Practical Programming in C
IAP 2010
Problem Set 1
Writing, compiling, and debugging programs. Preprocessor macros. C file structure. Variables.
Functions and program statements. Returning from functions.
Out: Monday, January 11, 2010. Due: Tuesday, January 12, 2010.
Problem 1.1
(a) What do curly braces denote in C? Why does it make sense to use curly braces to surround
the body of a function?
(b) Describe the difference between the literal values 7, "7", and ’7’.
(c) Consider the statement
double ans = 10.0+2.0/3.0−2.0∗2.0;
Rewrite this statement, inserting parentheses to ensure that ans = 11.0 upon evaluation of
this statement.
Problem 1.2
Consider the statement
double ans = 18.0/squared(2+1);
For each of the four versions of the function macro squared() below, write the corresponding value
of ans.
1. #define squared(x) x*x
2. #define squared(x) (x*x)
3. #define squared(x) (x)*(x)
4. #define squared(x) ((x)*(x))
Problem 1.3
Write the “Hello, 6.087 students” program described in lecture in your favorite text editor and
compile and execute it. Turn in a printout or screen shot showing
• the command used to compile your program
• the command used to execute your program (using gdb)
• the output of your program
1
Department of Electrical Engineering and Computer Science
6.087: Practical Programming in C
IAP 2010
Problem Set 1
Writing, compiling, and debugging programs. Preprocessor macros. C file structure. Variables.
Functions and program statements. Returning from functions.
Out: Monday, January 11, 2010. Due: Tuesday, January 12, 2010.
Problem 1.1
(a) What do curly braces denote in C? Why does it make sense to use curly braces to surround
the body of a function?
(b) Describe the difference between the literal values 7, "7", and ’7’.
(c) Consider the statement
double ans = 10.0+2.0/3.0−2.0∗2.0;
Rewrite this statement, inserting parentheses to ensure that ans = 11.0 upon evaluation of
this statement.
Problem 1.2
Consider the statement
double ans = 18.0/squared(2+1);
For each of the four versions of the function macro squared() below, write the corresponding value
of ans.
1. #define squared(x) x*x
2. #define squared(x) (x*x)
3. #define squared(x) (x)*(x)
4. #define squared(x) ((x)*(x))
Problem 1.3
Write the “Hello, 6.087 students” program described in lecture in your favorite text editor and
compile and execute it. Turn in a printout or screen shot showing
• the command used to compile your program
• the command used to execute your program (using gdb)
• the output of your program
1
