Prrogram C (Exam 3)

Strings: The “Null” Terminator

Is a special character used in C to mark the end of a string.

C strings are NOT their own (BLANK); they are just (BLANK) of (BLANK).

data type; array; characters.

Without the (BLANK) functions like (BLANK) or (BLANK) would not know where the string (BLANK), leading to (BLANK)

null terminator (‘\0’); printf; strlen; ends or “stops”; undefined behavior or “garbage” behavior — program crashes

A (BLANK) is a variable that stores the (BLANK) of another variable rather than a (BLANK)

Pointer; memory address; direct value

Dereferencing

Using the asterisk (*) operator to access or modify the value stored at the address the pointer is holding

Address-of Operator

Using the ampersand (&) to retrieve the memory address of a standard variable

Stack Memory

Memory managed automatically by the complier. It stores local variables and functions calls. It is fast but small and fixed in size.

Heap Memory

Memory managed manually by the programmer using malloc or calloc. It is much larger and flexible but slower to access.

Memory Leak

A condition where a program allocates memory on the heap but fails to free() it before the pointer is lost, wasting system resources

Pass by Reference

A method of passing arguments to a function where the address of the variable is passed instead of a copy of its value.

True or false; pass by reference allows a function to modify the original variable's value in the calling function (like main).

True

A (BLANK) is a (BLANK) that allows you to group variables of a different types (heterogenous data) under a single name.

Struct(structure); user-defined data type;

True or False; Like an Array (which holds the same type of data), a struct can not hold a char, an int, and a float all at once.

False

argc (Argument count)

An integer representing the number of arguments passed to the program from the command line (including the program name itself)

argv (Argument rector)

An array of strings (pointers to characters) where each string is one of the arguments passed

Calloc

Allocates memory and initializes all bytes to zero.

Malloc

Allocates a block of uninitialized memory (contains “garbage” values).

The FILE Pointer

FILE * is a specific data type (a structure) used by C to keep track of a file’s “state” (where you are currently reading or writing in that file)

Opens an existing file. Crucial: If the file does not exist, fopen returns null

mode “r” (Read)

Creates a new file. Crucial: If the file already exists, it contents are overwritten (deleted) immediately

mode “w” (write)

A definition for a special constant that signals when there is no more data to read from a file

EOF (End of File)