Unit 1: Introduction to Program Planning & C Programming

Vocabulary flashcards covering Unit 1 concepts: Program Design Tools, Algorithms, Flowcharts, History and Features of C, Character Sets, Tokens, Data Types, Storage Classes, Constants, and Qualifiers.

Program Design

The process of creating a plan or a set of instructions for a computer program that will enable it to solve a particular problem.

Algorithm

A precise, step-by-step set of ordered instructions written in simple English language for solving a computational problem.

Finiteness (Algorithm Characteristic)

The requirement that an algorithm must always terminate after executing a finite number of steps.

Definiteness (Algorithm Characteristic)

The requirement that each individual step of an algorithm must be stated clearly and precisely.

Effectiveness (Algorithm Characteristic)

The requirement that every step must be easily convertible into a program statement and executable exactly in a finite amount of time.

Generality (Algorithm Characteristic)

The property that an algorithm must be complete in itself so that it can be applied to solve all problems of a given type for any input data.

Flowchart

A graphical or pictorial representation of an algorithm that maintains the sequence of steps using standard symbols and directed lines.

Terminal Symbol (Flowchart)

An oval-shaped symbol used to denote the start, stop, begin, or end of a flowchart.

Input/Output Symbol (Flowchart)

A parallelogram symbol used in a flowchart for making data available for processing (input) or recording processed information (output).

Process Symbol (Flowchart)

A rectangular symbol in a flowchart that denotes any processing operation, including assignment operations.

Decision Symbol (Flowchart)

A diamond-shaped symbol that indicates a decision or switching operation to determine which alternative execution path to follow.

Connector (Flowchart)

A circular symbol used to connect different, separate parts of a flowchart.

Flow Lines (Flowchart)

Arrows that join two flowchart symbols to show the sequence and direction of execution flow.

Area of Circle Flowchart

A sequential flowchart that takes Radius as input, computes $\text{Area} = 3.14 \times \text{Radius} \times \text{Radius}$, displays the area, and terminates.

Even or Odd Flowchart

A branching flowchart that reads a number, evaluates if $\text{Number} \% 2 == 0$ using a decision diamond, and displays 'Even Number' if yes or 'Odd Number' if no.

Dennis Ritchie

The computer scientist who designed and wrote the C programming language at AT&T's Bell Laboratories in USA in $1972$.

ALGOL 60

A language developed in $1960$ by an International Committee for commercial, scientific, and system applications that failed to become popular because it was too abstract and too general.

Combined Programming Language (CPL)

A programming language developed at Cambridge University to reduce the abstractness of ALGOL 60, but was hard to learn and difficult to implement due to its large size.

Basic Combined Programming Language (BCPL)

A programming language developed by Martin Richards in $1967$ at Cambridge University to solve the problems of CPL; it was less powerful and too specific.

B Language

A programming language written around $1970$ by Ken Thompson that was also considered too specific.

Middle-Level Language

A description of C indicating that it bridges high-level and low-level concepts by combining features of BASIC and PASCAL with the direct manipulation of bits, bytes, and memory addresses.

Alt+F9

The keyboard shortcut key used to compile a program in a C development environment.

Ctrl+F9

The keyboard shortcut key used to run an executable program in a C development environment.

C Token

The smallest indivisible atomic unit in a C program recognized by the compiler, including keywords, identifiers, constants, strings, special symbols, and operators.

Keywords

Predefined reserved words in C (exactly $32$ in ANSI C) that carry a fixed, special meaning to the compiler and must always be written in lowercase.

Identifiers

User-defined names assigned to variables, functions, structures, and arrays consisting of letters, digits, and underscores, whose first character must be an alphabet or underscore.

Constants

Fixed values that do not change during the execution of a program.

Integer Constant

A numeric constant consisting of a sequence of digits with at least one digit, no decimal point, and an allowable range of $-32768$ to $+32767$ on a $16\text{-bit}$ machine.

Octal Integer Constant

An integer constant consisting of any combination of digits from the set $0$ through $7$, preceded by a leading $0$.

Hexadecimal Integer Constant

An integer constant that starts with $0x$ or $0X$ followed by a combination of digits $0$ through $9$ and letters $A$ through $F$ (or $a$ through $f$).

Real Constants

Numeric constants with a fractional part separated by a decimal point or written in exponential notation ($\text{mantissa } e \text{ exponent}$) to express continuous values.

Single Character Constant

A single alphabet, digit, or special symbol enclosed within a pair of single quotation marks, which carries a corresponding integer ASCII value.

String Constant

A sequence of characters enclosed within double quotation marks that is automatically terminated by the compiler with a null character (\0).

Escape Sequence

A backslash character constant consisting of two characters beginning with \ that functions as a single character in output operations (e.g., \n for new line, \t for horizontal tab).

Variable

A named data storage location that can hold a value and whose value can vary or change at different times during program execution.

Initialization

The process of assigning an initial value to a variable at the time it is declared in a program.

Data Type

A storage format specification in C that determines the type, legal range of values, and memory requirement allocated for a variable or function.

Primary Data Types

The fundamental built-in data types supported by C compilers: integer (int), character (char), floating-point (float), double-precision floating point (double), and void.

void Type

A primary data type that has no values, commonly used to indicate that a function does not return any value to the calling routine.

typedef

A C feature and keyword that allows users to define a meaningful identifier alias representing an existing data type to enhance program readability.

enum (Enumerated Data Type)

A user-defined data type where variables can only take values from a specified list of enumeration constants, which are assigned consecutive integer values automatically beginning with $0$.

Storage Class

A specification in C that determines the location, visibility (scope), default value, and lifetime of a variable.

Local Variable

A variable declared inside a function block that is stored in the stack, has local scope, defaults to a garbage value, and is destroyed when function execution terminates.

Global Variable

An external variable declared outside all functions that resides in the data segment, has program-wide scope, defaults to $0$, and exists throughout program execution.

auto (Storage Class)

The default storage class for local variables, allocated in internal memory with local scope, a garbage default value, and lifetime limited to its enclosing block.

static (Storage Class)

A storage class specifier that retains a variable's value across multiple function calls throughout the runtime of the program, initialized to $0$ by default.

extern (Storage Class)

A storage class specifier declaring a global variable that is stored in internal memory, has global visibility across functions, and persists as long as the program runs.

register (Storage Class)

A storage class specifier that requests a variable to be stored directly in a CPU register rather than internal RAM for faster execution speed.

Symbolic Constant (#define)

A constant defined via the #define preprocessor directive without a data type or trailing semicolon, used to enhance program modifiability and understandability.

const Qualifier

An ANSI C type qualifier used during variable declaration to inform the compiler that the variable's value must remain constant and cannot be modified by the program.

volatile Qualifier

A type qualifier notifying the compiler that a variable's value may be altered at any time by external sources outside the program, requiring it to be re-evaluated each time it is accessed.