2 + 3. Anatomy of a program

Question 1

when we run a program we are running

Answer 1

a) an object file
b) a machine language file

-computers understand machine language, and object files are in machine language

Question 2

object file

Answer 2

file containing object code

Question 3

use of xcode

Answer 3

to type in + edit your program files

Question 4

terminal utility

Answer 4

gives UNIX interface, used to enter UNIX commands to iMac

Question 5

terminal commands

Answer 5

cd: change directory
ls: show programs in folder
make: compiles program

Question 6

when compiling program

Answer 6

don’t type .cpp, just write the file name

Question 7

troubleshooting: ‘program’ is up to date

Answer 7

probably forgot to save edited program

Question 8

troubleshooting: no rule to make target ‘program’

Answer 8

mistyped filename or file not in current directory

Question 9

troubleshooting: use of undeclared identifier

Answer 9

syntax error, didnt declare a variable

Question 10

Use of // or /* */

Answer 10

a comment (ignored)

Question 11

include

Answer 11

allows program to use built-in facilities for input and output (IO)

Question 12

int main () {}

Answer 12

a function that returns an integer (int), function is called main

Question 13

return 0

Answer 13

main returns the integer 0

Question 14

{ }

Answer 14

used to define functions/processes

Question 15

variables

Answer 15

places which store values

Question 16

valid variable names

Answer 16

start w/ letter or underscore

rest is letters, digits, or underscore

Question 17

notes on using variables

Answer 17

• case sensitive eg. rate vs Rate vs RATE

- don’t use reserved keywords eg. int, for, while

Question 18

data type

Answer 18

what kind of thing you want to store in a variable

Question 19

Data types

Answer 19

• int
• double
• bool
• char
• string

Question 20

int

Answer 20

integers

Question 21

double

Answer 21

decimal number

Question 22

bool

Answer 22

true/false values

Question 23

char

Answer 23

used to hold a letter/digit or other symbol eg. “a” “&” or “ “ (a space)

Question 24

string

Answer 24

for sequences of characters eg “hello”

Question 25

note on double: float

Answer 25

can be used for smaller less precise numbers

Question 26

note on string

Answer 26

data type not built in, must include string library at top #include

Question 27

variable declaration

Answer 27

variables + data types must be declared before use

Question 28

giving variables values

Answer 28

a) reading eg. cin >> x; b) assignment eg. sum = 0; name = "Mary"; always give variables an initial value before use

Question 29

=

Answer 29

the assignment operator

Question 30

iostream

Answer 30

contains definitions for cout and cin

Question 31

cout and cin arrow directions

Answer 31

cout << | cin >>

Question 32

/

Answer 32

divides eg. 10/3 = 3 (for int)

Question 33

%

Answer 33

remainder eg. 10%3 is 1

Question 34

integer division

Answer 34

only if both operands are integers that division is integer division

Question 35

cmath library common commands

Answer 35

``` cos/sin/tan exp log pow sqrt fabs ```

Question 36

assigning int to a decimal value

Answer 36

by assigning a decimal value to an int variable, you effectively drop the decimals ``` eg. int i; double x = 3.1415; i = x; i will equal 3 ```