C++ Basics - Terminology Reference

This lesson provides a comprehensive reference of all the key C++ terminology you'll encounter throughout Chapter 1. Think of it as your programming vocabulary guide - these are the essential terms every C++ programmer needs to know.

Complete Terminology Guide

Program Structure & Execution

Term Definition Example
Program A set of instructions that tells the computer what to do A complete C++ application
Statement A single instruction that tells the computer to perform some action, must end with a semicolon int x = 5;
Function A named group of statements that perform a specific task main(), calculateArea()
main() function The special function where program execution begins; every C++ program must have one int main() { return 0; }
Preprocessor A tool that processes directives (like #include) before compilation Handles
#include <iostream>
Header file A file containing declarations that can be included in programs iostream, string
#include Preprocessor directive that includes library functionality #include <iostream>
return 0 Statement that tells the computer the program finished successfully End of main function
Compilation The process of converting source code into executable program Converting .cpp to .exe
Compiler Tool that translates C++ code into machine language g++, MSVC, clang

Data Storage & Variables

Term Definition Example
Object A piece of memory that can store values Any variable in memory
Variable A named object that gives us a way to refer to stored data int age;
Data type Defines what kind of data can be stored int, double, char
Declaration Tells the compiler about a variable's type and name int age;
Definition Actually creates the variable and allocates memory Same as declaration in C++
Initialization Giving a variable its first value when it's created int age = 25;
Assignment Storing a new value in an existing variable using the = operator age = 26;

Data Types

Term Definition Range/Usage
int Data type for whole numbers -2,147,483,648 to 2,147,483,647
double Data type for high-precision decimal numbers 15-16 digits precision
char Data type for single characters, enclosed in single quotes 'A', '5', ' '
bool Data type for true/false values true or false
string Data type for text of any length, requires #include <string> "Hello World!"
float Data type for decimal numbers with less precision than double 6-7 digits precision
short Data type for smaller integers -32,768 to 32,767
long Data type for larger integers Platform dependent

Values & Operations

Term Definition Example
Literal A fixed value written directly in code that never changes 5, 3.14, "hello"
Integer literal Whole numbers written directly in code 5, -3, 0
Floating-point literal Decimal numbers written directly in code 3.14159, 0.5
String literal Text enclosed in double quotes "Hello World!"
Operator A symbol that performs an operation on values +, -, *, /, =
Operand The values that operators work with In 5 + 3, both 5 and 3
Expression A combination of values, variables, and operators that produces a result x + y * 2
Evaluation The process of calculating an expression's result 2 + 3 * 4 becomes 14
Precedence Rules determining which operations are performed first in expressions * before +

Common Operators

Term Symbol Description Example
Assignment operator = Assigns a value to a variable x = 5;
Addition + Mathematical addition 5 + 3
Subtraction - Mathematical subtraction 10 - 4
Multiplication * Mathematical multiplication 6 * 7
Division / Mathematical division 15 / 3
Output operator << Sends values to std::cout cout << "Hello";
Input operator >> Reads values from std::cin cin >> age;

Input & Output

Term Definition Usage
iostream Library that provides input and output functionality #include <iostream>
std::cout Console output stream for displaying text on screen std::cout << "Hello";
std::cin Console input stream for reading data from keyboard std::cin >> age;
std::endl End line manipulator that creates a new line and flushes output buffer cout << "Hi" << endl;
Buffer Temporary storage area for input/output data Internal I/O storage
Chaining Using multiple << or >> operators in sequence cout << "Age: " << age;

Code Documentation & Style

Term Definition Example
Comment Text in code that explains what the code does, ignored by compiler // This is a comment
Single-line comment Comment that spans one line, uses // // Calculate total
Multi-line comment Comment that can span multiple lines, uses /* */ /* This spans multiple lines */
Pseudocode Human-readable blueprint for developing software Plain English program steps
Whitespace Spaces, tabs, and newlines used to format code for readability Spaces between words
Indentation Consistent spacing used to show code structure and nesting 4 spaces or 1 tab
Formatting The visual arrangement of code to improve readability Consistent spacing

Naming & Conventions

Term Definition Example
Identifier A name used to identify variables, functions, etc. studentAge, calculateTotal
Keyword A word reserved by C++ with special meaning, cannot be used as variable names int, return, if, while
camelCase Naming convention where first word is lowercase, subsequent words capitalized studentAge, totalScore
snake_case Naming convention using underscores between words student_age, total_score
Case sensitive C++ distinguishes between uppercase and lowercase letters in names Age ≠ age

Initialization Types

Term Syntax Description
Copy initialization int x = 5; Initialization using equals sign
Direct initialization int x(5); Initialization using parentheses
Uniform initialization int x{5}; Modern initialization using braces

Error Prevention & Safety

Term Definition Why It Matters
Undefined behavior When program behavior is unpredictable due to programming errors Can crash programs or produce wrong results
Uninitialized variable A variable declared without an initial value, contains garbage data Causes unpredictable behavior
Garbage value Random data left in memory from previous use Found in uninitialized variables

Essential Symbols

Symbol Name Usage Example
; Semicolon Required at end of most statements int x = 5;
{ } Curly braces Group code together, define code blocks int main() { }
" " Double quotes Enclose string literals "Hello World!"
' ' Single quotes Enclose character literals 'A'
( ) Parentheses Function calls, grouping expressions main(), (x + y)

Program Development Process

Term Definition When Used
Algorithm Step-by-step procedure for solving a problem Before writing code
Testing Process of verifying that a program works correctly with different inputs After writing code
Debugging Process of finding and fixing errors in code When problems occur
Iterative development Approach of starting simple and gradually adding features Throughout development

How to Use This Reference

  1. Before each lesson - Review terms that will appear
  2. During lessons - Look up unfamiliar terms quickly
  3. After lessons - Test your understanding of terminology
  4. Before quizzes - Study definitions for assessment prep

Study Tips

💡 Mastering Terminology
• Use terms in sentences - Practice explaining concepts
• Connect related terms - Understand how concepts link together
• Practice with examples - See terms used in actual code

Ready for the Quiz?

Now that you have the complete terminology reference, you're ready to test your understanding with the chapter quiz.

🎯 Next Step
Take the quiz to test your knowledge of these fundamental C++ terms. Don't worry if you need to refer back to this guide - that's what it's for!