Midterm Review - CSCI 1730

how do you know if a line in your source code is a preprocessor directive?

begins with a "#"

ex. #include

what does "compile" do?

turn the source code to an object code

what does "link" do?

turn the object code to an executable

what are the format specifiers?

begin with % and are used as placeholders to define the format and type of data to be printed

format specifier to print base 10 signed int

%d

format specifier to print base 10 unsigned int

%u

format specifier to print floating point values

%f

format specifier to print pointers

%p

format specifier to print hexadecimals

%x

format specifier to print characters

%c

format specifier to print strings

%s

valid names for a makefile

makefile

Makefile

default target

first target defined in the makefile

how can target dependencies be specified?

after the target name and the colon(:), specify a list of space-seperated dependencies

how are strings represented in C

data type is just an array of characters

diff b/w array and array of char

array of char to quaify as a string in C, the special null charcter (\0) must be the last charcter

diff b/w array and array of char

null character is used to indicate the end of the string

declare a pointer

how to obtain the memory of address of variable?

-use the "address of" operator &

-ptr = &x;

how do you retrieve the data value that a pointer points to? how do you update the data value using that pointer?

- use dereference operator*

- int y = *ptr;

- *ptr = 10

6 phases of a C program

1. editing in the editor

2. preprocess - processes the code

3. compile - compiler created the object file and stores it in the dicks

4. link - where executable files are created from object

5. load - where the code is put into a memory disk by the loader

6. execute: where the code is run and executed

compile and linking a c program

use command $ gcc -o filename filename.c

running a c program

use command $ ./filename

make utility

make is used in c and is incorporated in makefile

makefiles with variables

adding variables makes it very useful for multiple files

-Wall -pedantic-error flags

catch potential bugs with code

fundamental data types

char, int, float, double

data types modifiers that can combine with earlier types

signed, unsigned, short, long

signed

ability to look at negative numbers

0(+)

1(-)

char size

1 byte

unsigned char

8 zeros

sizeOf()

to check the size

& bitwise

compares each bit and does AND

| bitwise

compare each bit and does OR

^ bitwise

compares each bit and does XOR

~ bitwise

NOT

bits are flipped

<< left shift

shifts bits to left

>> right shift

shifts bits to the right

bitwise operators

- manipulate individual bits within a variable

- helps use less memory

arrays

Series of elements of the same type placed adjacently and can be referenced by indexes in a unique identifier

arrow operator

dereference operator which can be used with pointers to structs and can direct access the members

stack

used for mainly static memory location

heap

is used for dynamic memory allocation for storing objects and data structures that require a longer life