Identifiers, Variables, Keywords, and Data Types in C

Flashcards covering key terms, data types, variable rules, keywords, and identifiers for Week 4 C programming fundamentals.

Tokens in C

The individual elements in a C program that are identified by the compiler, including operators, keywords, identifiers, constants, special symbols, and strings.

Keyword

A pre-defined or reserved word in the C compiler that performs a specific function, consists only of lowercase letters, and cannot be used as an identifier.

Identifier

A user-defined name given to program elements such as variables, functions, and arrays, consisting of alphanumeric characters and underscores, starting with a letter or underscore.

Variable

A named memory location used to store a value during program execution whose content can change while its name remains constant.

Variable Declaration

The process of informing the compiler of a variable's name, data type, and scope/lifetime before it is used in executable statements.

int Data Type

A basic C data type representing whole numbers (e.g., $3$, $7$, $+8$, $-9$, $1000000$) using the format specifier $\%d$ or $\%i$.

float Data Type

A C data type used for numbers with a decimal point (e.g., $5.8$, $9.0$, $-5.6789$, $+0.0032$) using the format specifier $\%f$.

char Data Type (Single Character)

A C data type representing a single letter, symbol, or number enclosed within two single quotes (e.g., 'B', 'r', '*', '3') using the format specifier $\%c$.

char Data Type (String)

A series of characters enclosed within double quotes (e.g., "Ms.", "Hi!") formatted using the specifier $\%s$.

double Data Type

A C data type used for bigger or larger numbers with a decimal point (e.g., $123456789.123$) using the format specifier $\%f$.

Case Sensitivity

The C language rule where uppercase and lowercase letters are not equivalent, treating names like 'name' and 'Name' as two distinct identifiers.