1.8. Multiple Choice Exercises¶

Answer the following Multiple Choice questions to assess what you have learned in this chapter.

What is a program in computer science?

a planned series of events, a schedule

This is a definition of a program, just not in the computer science sense.

a translated language that is easy for the computer to understand

This is actually called a low-level language!

a sequence of instructions that specifies how to perform a computation

You can write these instructions to accomplish pretty much anything you want!

a general process for solving a category of problems

This is actually called an algorithm!

What is the function of the compiler?

It loads the program from its saved location and makes the computer execute it.

This is the function of an executor. If you use a compiler, you must also use an executer to run your code.

It reads a high-level program and translates everything at once, before executing any of the commands.

If there are any errors in your code, the program will not compile. It is an all-or-nothing process.

It translates the program from the low-level language you coded in to a high-level language that the computer can understand.

You, the programmer, write your program in a HIGH-level language. It is then translated to a LOW-level language that the computer can understand.

It translates the program line-by-line, alternately reading lines and carrying out commands.

This is the function of an interpreter.

What is the difference between source code and object code?

Source code can contain simple things like variables and values. Object code can contain more complex objects like data structures.

Contrary to it's name, object code has nothing to do with creating objects!

Object code can contain simple things like variables and values. Source code can contain more complex objects like data structures.

Source code and object code both contain variables, values, and data structures. They're just written in a different way.

Object code is the code that your program is written in. Source code is the translated version of this code that the computer can understand.

You seem to have things a bit mixed up!

Source code is the code that your program is written in. Object code is the translated version of this code that the computer can understand.

The computer can either use an interpreter or a compiler to make the translation.

Multiple Response What are the basic functions that appear in every programming language?

math operations

This is how your program can carry out complex calculations!

debugging

Debugging is the process of finding and fixing errors AFTER you have written your program. It's not one of the basic functions of a programming language.

input/output from the terminal and saved files

This allows your program to communicate with data either from the user, or from the user's saved files.

testing for conditions

This is why you would consider using conditional statements in your program.

repetition

This is why you would consider using a loop in your program.

What type of error would the following code cause? Assume you are trying to calculate the volume of a cylinder:

int radius = 7;
int height = 8;
double volume = 3.14 * radius * height;

syntax error

There is nothing wrong with the structure of this program.

run-time error

There are no errors that will surface at runtime.

semantic error

This is not the correct formula for calculating the volume of a cylinder. This program will go on to calculate the wrong volume because it doesn't know any better.

no error

Take a look at the area formula.

What type of error would the following generate? Assume you are trying to calculate the volume of a cylinder:

int radius = 7;
int height = 8
double volume = 3.14 * r * r * height;

syntax error

You are missing a semicolon on the second line, and you are using the variable r without defining it on the third line. your program will not compile.

run-time error

There are no errors that will surface at runtime.

semantic error

Everything looks good with your volume calculations.

no error

Take a closer look at the structure of the code.

Multiple Response C++ is a(n) ________.

formal language

all programming languages are formal languages!

natural language

C++ certainly did not evolve naturally!

foreign language

C++ might seem foreign to you, but it's used globally!

high-level language.

C++ must be translated before the computer can understand!

low-level language.

The computer doesn't understand C++ until it gets translated!

Multiple Response Which of the following is true about writing a program.

The compiler ignores anything after //.

This is called a comment, which you can use to describe your code to outsiders who might not understand.

There is no limit the number of statements you can put in main.

You can include as many statements as you want to, but it is good practice to keep the main as short as possible.

Program execution begins at the first line of code.

Program execution actually begins with main and then happens in order, from top to bottom.

main is enclosed by squiggly brackets { }.

The main program and all functions in C++ are enclosed by squiggly brackets.

The end of each statement is marked with a colon :.

Actually, each statement is terminated with a semi colon ;.

Multiple Response Which is true about programming languages?

Low-level languages are only used for a few special applications.

Low-level languages take more time to write, and they are much harder to understand, so they aren't used often.

Programs written in low-level languages must be translated before they can be run.

Low level languages are already written in a language that your computer can understand, so they don't need to be translated!

It's easier to program in a high-level language than a low-level language.

High-level languages take less time to write, they are much easier to understand, and they are more likely to be correct!

Computers can only execute programs written in low-level languages.

This is why most programs need to be translated before they can be run!

High-level languages can run on many different kinds of computers without an issue.

This is called portability.

Q10

You were asked to parse through your program, what should this entail?

You should walk through your program line by line to make sure it's that your code doing what it is supposed to.

This is how you would detect a semantic error. Parsing doesn't involve semantic errors.

You should search through your program for syntax errors.

Parsing involves looking at the syntactic structure of your program.

You should translate your program to object code.

This would be quite a chore! Luckily you have an interpreter or a compiler to do that for you!

You should run your program and check for run-time errors.

Parsing doesn't involve run-time errors.