CS50 Flashcards
(105 cards)
1
Q
Computers really only understand what?
A
Zero’s and Ones
2
Q
What is binary system
A
Zero’s and Ones
3
Q
Computers’ use powers of what?
A
Powers of 2
4
Q
How is a “1” represented in computer value?
A
001
5
Q
How is a “2” represented in computer value?
A
010
6
Q
How is a “3” represented in computer value?
A
011
7
Q
How is a “4” represented in computer value?
A
100
8
Q
Zeros and ones– the so-called binary system–
are what a computer scientist would generally call what?
A
a bit, or binary digit.
9
Q
Inside of a computer is millions,
billions of things that are just smaller than that, called,
_____ or switches, that you just turn on and off.
A
transistors
10
Q
How many “bits” equal a “byte?”
A
8 bits equal one byte
11
Q
Unicode allowed us to represent what new thing with zero’s and one’s?
A
Color
12
Q
What is an algorithm?
A
step by step instructions
13
Q
What is another term for “actions?”
A
Functions
14
Q
What are “conditions”
A
Actions points for a decision
15
Q
What is a Boolean expression?
A
Something that is either true or false, yes or no
16
Q
What is the goal of an algorithm?
A
Finding “good” and “fast” solutions to problems
17
Q
Math inequalities are really _____ expressions.
A
Boolean
18
Q
What is an array?
A
A list, or way of storing multiple pieces of information in a variable, not just a number.
19
Q
Multi-threading allows me to do…..
A
multiple things at a time
20
Q
The goal in programming is…
A
to take very deliberate baby steps toward end goal
21
Q
Scratch website?
A
Scratch.MIT.edu
22
Q
A multi-threaded program is a program that can do….
A
multiple things at once.
23
Q
0 and 1 represent what?
A
False (0) and True (1)
24
Q
What does “PRINTF” stand for?
A
Print Formatted or
25
In printf("hello, world\n"); what does printf represent?
FUNCTION or activity for the computer to perform (SAY)
26
In printf("hello, world\n"); what does HELLO WORLD represent?
The computer's parameter, argument, or customization.
27
In printf("hello, world\n"); what does the \n represent?
Moving the cursor of computer to the next line...kind of like hitting the ENTER key on keyboard
28
What does "true" represent in computer language?
It represents ON or 1.
29
How would I create a forever loop of saying "hello, world"?
while (true)
{
printf("hello, world\n");
}
The WHILE (TRUE) will cause the action to be looped forever.
30
Why type of loop can I write in C if I want a action to be repeated only a certain number of times then stop?
I should write a "for" loop.
31
What is the syntax of a "for loop" in C programming language?
for ( init; condition; increment ) {
statement(s);
}
32
Programmers almost always start counting from what number?
Zero
33
What does "int" stand for in C programming?
Integer (whole number; a number that is not a fraction)
34
A variable is nothing but a name given to a _____ area that our programs can manipulate.
storage
35
Each variable in C has a specific type, which determines what?
1. the size and layout of the variable's memory
2. the range of values that can be stored within that memory
3. the set of operations that can be applied to the variable.
36
The name of a variable can be composed of what?
1. letters
2. digits
3. underscore character
37
The name of variables must begin with what?
either a letter or an underscore.
38
Is C programing language case sensitive?
Yes
39
What are the 5 basic variable types in C Programming?
1. char
2. int
3. float
4. double
5. void
40
What does the semi-colon ; mean in C Programming?
it is the end of thought
41
What is the "less than" symbol?
42
What is the "greater than" symbol?
>
43
What is a condition?
A statement that tells the computer if this then do that.
44
Example of CONDITIONAL STATEMENT?
```
if (x < y)
{
printf {"x is less than y\n" };
}
else (x > y)
{
printf {"x is greater than y\n" };
}
else
{
printf {"x is equal to y\n" };
}
```
45
What is an ARRAY?
A special type of variable (or list) that allows for the storage of data back to back, to back, to back.
46
What does "argv" stand for in C programming?
Argument Vector which is my designated ARRAY or list name.
47
What does "main" stand for in C programming?
It is a special default FUNCTION which refers to the main piece of code that gets executed automatically when a program is run.
48
What does CPU stand for?
Central Processing Unit
49
What does CPU represent?
Brain of computer
50
An _____ _____ has designated that certain patterns of 0's and 1's shall mean certain things.
Intel brain (CPU)
51
What are the software programs which convert/translate source code into machine code known as?
COMPILERS
52
C is a language that is usually _____ or converted from source code to machine code.
COMPILED
53
If I want to translate the source code I have written into machine code (0's and 1's) I have to do what first?
Feed my source code into the machine as INPUT through a special program called a COMPILER.
54
A COMPILER has a set of _____ that know how to convert special keywords like main, printf, etc into machine code patters of 0's and 1's so the CPU can understand.
algorithms
55
What are 2 examples of programs that do not run on my computer but, rather, on the cloud?
Python
| JavaScript
56
What does IDe stand for?
Integrated Development
57
What is IDe?
Web-based programming environment that is built on top of open source software called Cloud9
58
What is the CS50 cloud based environment known as?
CS50 IDE
| located at cs50.io
59
What does pedagogical mean?
related to teaching
60
Any program I write that's written in the C language
| should be named something _____ _____, by convention.
dot c or .c
example:
hello.c
61
In the environment of CS50 IDE, one is using
| an operating system called _____.
Linux
62
Linux is reminiscent of another operating system, generally known as _____.
Unix
63
Linux is particularly known for having what type of environment?
Command Line Environment, CLI.
64
What does CLI stand for?
Command Line Environment
65
What "flavor" of Linux is CS50 IDE using?
Ubuntu which is just a version of Linux
66
What is "clang" in the C Language?
a COMPILER which is pre-installed in CS50 IDE
67
What is the $ mean in the command line?
A convention or PROMPT that means type your commands here.
68
The default name for programs when you don't specify a name for your program is just _____.
a.out
69
Dot slash of ./a.out just means what?
Hey, CS50 IDE, run a program called a.out
| that's inside my current directory.
70
What does the dot of ./a.out mean?
Current directory
71
The less that happens on your computer screen, the more likely your code is _____, at least syntactically.
correct
72
What is "clang" short for?
C Language
73
A computer is literally going to do what?
Only what I tell it to do
74
Whenever I change my source code I have to do what in order to allow my computer to read the change?
Run my change through the compiler again.
75
What does a.out stand for?
Assembly Output
76
What are other terms for command line arguments?
Flags
| Switches
77
What do command line arguments (flags or switches) influence?
The behavior of a program
78
What does -o represent?
Output
It is an output command line argument or flag that creates a new folder other than a.out (default)
79
Example of creating a new folder in command line?
clang -o name hello.c
80
What does "ls" command do?
Lists the files in the current working directory
81
What does rm stand for?
remove command
82
The rm (i.e., remove) command is used to _____ files and directories
delete
83
What does the asterisk * mean in the command line?
That's an executable, or runnable program, that one can run by doing dot slash, and then it's name.
84
How do I create a new source file in the current working directory with the MAKE program?
simply type in the command line: make filename
85
Do I need to include the -o or .c to create a new source folder in the command line with the MAKE program?
No, because MAKE automatically assumes that the new file is going to be made from a source code file ending in .c or hello.c
86
Is MAKE a compiler program?
No
87
MAKE is a a convenience program that knows how to trigger a _____ to run so that one can use it.
compiler
88
What does "cd" command stand for?
change directory
89
What allows one to move forward, backwards, and open up different folders within the command line interface
without using a mouse?
cd (change directory) command
90
What does "mkdir" mean?
make directory
91
What does "mkdir" command do?
Makes a new directory (folder)
92
What does "rm" stand for?
remove
93
What does "rmdir" stand for?
remove directory
94
In stdio.h what does the io mean?
```
i = Input
o = output
```
95
#include command enables us to use what?
printf
96
printf produces what?
output
97
In order to use printf what line MUST I have at the top of my code?
#include because it enables output
98
In any C program I write I have to start the code with what?
```
int main (void)
{
```
}
99
Strings are like _____.
sentences or sequence of characters
100
What is the C command to get a string from the user?
get_string()
101
When I do not want to provide specific input into a puzzle piece or a function how would I write its string?
With empty open and closed parenthesis.
102
When I call get_string (), where would I place the return value results?
In C I would use a VARIABLE to store the get_string() return value results.
103
What does the equal sign = mean in C?
It is the "assignment operator" which tells the computer to move a value from the right side to the left side.
104
What does this mean to the computer:
{
string name = get_string();
}
Hey, computer, give me a string (a sequence of characters) with no inputs and call that string "Name."
105
What special syntax would I use to have a "placeholder?"
%s
