C Programming/Variables/Quizes/Answers

Question 1
List all the native C types. State wether they store integer or floating point data.


 * char  integer data
 * short integer data
 * int   integer data
 * long  integer data
 * float floating point data
 * double floating point data

Question 2
Declare an integer with the name totalMoney.


 * int totalMoney;

Question 3
What storage type would you use for the following ideas?

The area of a triangle?


 * A double. Its unlikely that the area of a triangle is always going to be an integer.

The number of people in the United States?


 * An integer. You can't have half a person.

The average number of people living in a house?


 * A double. Ok, I lied.  In this case, you can have half a person.  The lesson here- don't pay attention to just what the data is, but how you plan to use it.

The amount of money in your wallet?


 * A double. You likely have some change.  The other thing you could do is to count money in cents and hold it in an integer.  If you need to be 100% accurate, you want to do it the second way (floats round the number to the nearest power of 2).

The number of hours you worked last week?


 * An integer if you only can work full hours. A double if you can work half hours.

Question 4
What real type would you use for the following ideas?

The area of a triangle?


 * Area. It says exactly what it stores.  If you know the units (square cm, square inches, etc) you should use that instead.

The number of people in the United States?


 * People. Population would also work well.

The average number of people living in a house?


 * AveragePeople. People is also good, if you don't need an integer number of people elsewhere.

The amount of money in your wallet?


 * Money. If you hold the number of cents instead of dollars, you probably want to use Cents instead.

The number of hours you worked last week?


 * Hours. This is an easy one.

Question 5
What names would you use to describe them?

The area of a triangle?


 * triangle, triangleArea, or something similar.

The number of people in the United States?


 * usPopulation, or something similar.

The average number of people living in a house?


 * peoplePerHouse, householdSize, or something similar.

The amount of money in your waller?


 * moneyInWallet, or something similar.

The number of hours you worked last week?


 * workedLastWeek

Question 6
What are the values of x, y, and z after each line of the following code?

int x,y,z;


 * We don't know, we didn't assign them any. All 3 are random.

x=7;


 * x=7. y and z are still random.

y=2*x+5;


 * x=7. y=19.  z is still random.

z=y+x;


 * x=7. y=19.  z=26

x=9;


 * x=9 y=19  z=26.  Notice that only x changed.

z=x-8;


 * x=9 y=19 z=1