Section One - C Primer Flashcards
Daemons
Program with no GUI and run in the background.
command line tools
Programs that run for a short time in terminal.
Function
A list of instructions for computer to execute.
Variable
Place where data is stored.
short, int, long
These three types are whole numbers.
float, double
Floating point number – a number that can have a decimal point.
char
One byte integer that we usally treat as a character.
pointers
A Pointer holds a memory address. Declared using a asterisk.
struct
A struct is a type made up of other types.
if/else
if (conditional) {
// execute this code if the conditional evaluates to true
} else {
// execute this code if the conditional evaluates to false }“==”
Are they equal?
“!=”
Are they not equal?
&&
Logical AND – true if and only if both are true.
||
Logical OR – false if and only if both are true.
!
Logical NOT – true becomes false, false becomes true.
boolean variable
A variable that can be true or false. BOOL someVarName =
else if
if (truckWeight <= 0) {
printf("A floating truck\n");
} else if (truckWeight < 40000.0) {
printf("A light truck\n");
} else {
printf("A heavy truck\n");
}conditional (ternary) operator
int minutesPerPound = isBoneless ? 15 : 20;
function frame
Think of frame as a blackboard that you scribble on while function is running.
stack
is a place in the computer memory where all the variables that are declared and initialized before runtime are stored.
Automatic values – variables are automatically destroyed when function ends.
heap
is the section of computer memory where all the variables created or initialized at runtime are stored.
three memory segments
text (code) segment
stack segment
heap segment
recursion
a function that calls itself.
static variable
A variable with static storage duration has a permanent storage location. It retains its value throughout the execution of the program. Only accessible from the code in the file it was declared.
global variable
These variables can be accessed (ie known) by any function comprising the program.
printf()
a function that accepts a string argument. can take literal string called Format string by surrounding text in double quotes.
printf() tokens
token values inside string are replaced with values by variables at end of string. %i or %d int %c char %f float %lf double %s string %lo octal %lx hexadecimal %e scientific notation %p pointer
modulus operator %
Like / but returns the remainder instead of the quotient.
cast operator
is the type you want placed in parentheses to the left of the variable you want converted. example: converts int into a float (float)3
increment operator
x++
decrement operator
x–
increment operator shorthand
x += 5; // x = 10
-=, *=, /=, and %=
integer
a number without a decimal point. A whole number.
NSInteger, NSIUinteger
Apple created to integer types that are 32-bit on 32-bit platforms and 64-bit on 64-bit platforms. They are the same as long and unsigned long.
break loop
sometimes its nesecary to break out of a loop. break;
continue loop
someimes its nesecary to forget this and start next run. example: if (i % 3 == 0) {
continue;
}
dereferencing the pointer
reading data at the address of the pointer.
sizeof()
Allows a program to determine how much memory is required by a particular type
sizeof(int)
modf()
modf takes a double and saves both the integer and the fraction. It returns the fractional part and saves the int to an address.
fractionPart = modf(pi, &integerPart);
pass-by-reference
you supply an address and you put a number there.
malloc()
You claim buffer memory using malloc() from the region of memory known as the heap. When done using the buffer you use function free()
float *startOfBuffer;
startOfBuffer = malloc(1000 * sizeof(float));
while loop
int i = 0;
while (i < 12) {
printf("%d. Aaron is Cool\n", i);
i++;
}for loop
for (int i = 0; i < 12; i++) {
printf(“%d. Aaron is Cool\n”, i);
}
