School of Engineering and Applied Science Department of Computer Science CSci 49 -- Introduction to C Computing http://www.seas.gwu.edu/~csci49/spring06 Prof. Michael B. Feldman mfeldman@gwu.edu

Part I. Integer and float arithmetic.

int iResult, num1 = 25, num2 = 40, num3 = 17, num4 = 5;
float fResult, val1 = 17.0, val2 = 12.78;

For each of these assignment statements, what will the result be in iResult or fResult? First compute the results manually and fill in the "predicted results" column of the table. Then, use the program programs49/Arithmetic.c as a way to test your predictions and fill in the "actual results" column. Use the fourth column for any comments you may have. Make sure you understand why each actual result is what it is!
 

Assignment Statement	Predicted Result	Actual Result	Explanatory Comments
iResult = num1 / num4;
fResult = num1 / num4;
iResult = num3 / num4;
fResult = num3 / num4;
fResult = val1 / num4;
fResult = val1 / val2;
iResult = num1 / num2;
fResult = (float) num1 / num2;
fResult = num1 / (float) num2;
fResult = (float) (num1 / num2);
iResult = (int) (val1 / num4);
fResult = (int) (val1 / num4);
fResult = (int) ((float) num1 / num2);
iResult = num3 % num4;
iResult = num 2 % num3;
iResult = num3 % num2;
iResult = num2 % num4;

 

Part II: Operator precedence.

int iResult, a = 10, b = 8, c = 6, d = 5, e =2;

and the program programs49/Precedence.c.

Assignment Statement	Predicted Result	Actual Result	Explanatory Comments
iResult = a - b - c - d;
iResult = a - b + c - d;
iResult = a + b / c / d;
iResult = a + b / c * d;
iResult = a / b * c * d;
iResult = a % b / c * d;
iResult = a % b % c % d;
iResult = a - (b - c) - d;
iResult = (a - (b - c)) - d;
iResult = a - ((b - c) - d);
iResult = a % (b % c) * d * e;
iResult = a + (b - c) * d - e;
iResult = (a + b) * c + d * e;
iResult = (a + b) * (c / d) % e;

(end of lab)