Keywords in C++: An Overview
Keywords in C++ are reserved terms in the C++ programming language that have preset meanings. These words cannot be used as identifiers (for example, variable names) yet are critical to program structure and functionality. Examples of keywords in C++ programming include "int," "if," "while," and "class." They are essential building blocks for writing code, aiding in the definition of data types, control flow, and object-oriented notions. Understanding and effectively using keywords is critical for building efficient and error-free C++ programs.
Tokens in C++
Tokens, the smallest individual unit, comprise a C++ program. Tokens can be keywords, identifiers, constants, operators, or punctuation marks, among other things.
Tokens in C++ are classified into six types:
- Special symbols
What is a Keyword in C++?
Keywords or reserved words have some specific meaning to the compiler of C++ programs and it is always written in lower cases. Keywords in C++ language are generally used for serving some special functions such as "void", "int", "public" and many more in languages.
Types of keywords in C++
If the question is how many keywords are in C++ then the answer will be, that C++ language has 32 various types of keywords.
Explanation of Keywords in C++
- Asm: It is used to declare a block of code that has to be passed to the assembler.
- auto: This keyword is a storage class specifier that is used for defining objects in a particular block.
- break: This statement terminates any switch statement or any loop.
- case: This keyword is used specifically within a switch statement to specify a match for the expression of the statement.
- catch: It specifies which actions have to be taken when an exception occurs.
- char: This is one of the fundamental data types in C++ language that defines character objects.
- class: It is used to declare a user-defined data type that encapsulates any data members and operations or member functions of a particular class.
- const: This keyword helps to define objects whose value will not alter throughout the lifetime of execution of that particular program.
- continue: It transfers control to the starting point of a loop.
- default: This keyword handles expression values in a switch statement that could not be handled by case.
- delete: It is a memory deallocation operator.
- do: indicate the start of a do-while statement in which the sub-statement is executed repeatedly until the value of the expression is logical-false.
- double: Fundamental data type used to define a floating-point number.
- else: Used specifically in an if-else statement.
- enum: To declare a user-defined enumeration data type.
- extern: An identifier specified as an extern has an external linkage to the block.
- float: Fundamental data type used to define a floating-point number.
- for: Indicates the start of a statement to achieve repetitive control.
- friend: A class or operation whose implementation can access the private data members of a class.
- long: A data type modifier that defines a 32-bit int or an extended double.
- new: Memory allocation operator.
- operator: Overloads a C++ operator with a new declaration.
- private: Declares class members who are not visible outside the class.
- protected: Declares class members who are private except to derived classes
- public: Declares class members who are visible outside the class.
- register: A storage class specifier that is an auto specifier, but which also indicates to the compiler that an object will be frequently used and should therefore be kept in a register.
- goto: This keyword helps to transfer the power of the control to a specified label.
- if: It indicates the starting point of an if statement to achieve selective control.
- inline: A function specifier that indicates to the compiler that inline substitution of the function body is to be preferred to the usual function call implementation.
- int: Fundamental data type used to define integer objects.
- return: Returns an object to a function’s caller.
- short: A data type modifier that defines a 16-bit int number.
- signed: A data type modifier that indicates an object’s sign is to be stored in the high-order bit.
- sizeof: Returns the size of an object in bytes.
- static: The lifetime of an object-defined static exists throughout the lifetime of program execution.
- struct: To declare new types that encapsulate both data and member functions.
- switch: This keyword is used in the “Switch statement”.
- template: parameterized or generic type.
- this: A class pointer points to an object or instance of the class.
- throw: Generate an exception.
- try: Indicates the start of a block of exception handlers.
- typedef: Synonym for another integral or user-defined type.
- union: Similar to a structure, struct, in that it can hold different types of data, but a union can hold only one of its members at a given time.
- unsigned: A data type modifier that indicates the high-order bit is to be used for an object.
- virtual: A function specifier that declares a member function of a class that will be redefined by a derived class.
- Void: This keyword identifies the absence of a type or function parameter list.
- volatile: This particular keyword defines an object that may vary in value in a way that is undetectable to the compiler.
- while: This keyword helps to start a while statement and end a do-while statement
1. What are the keywords of C++?
Keywords in C++ are reserved words with specified definitions, such as "if" and "class."
2. How keywords are different from identifiers?
Identifiers are user-defined names for variables, functions, and other things while keywords have predetermined meanings and cannot be used as variable names.
3. How many keywords are there in C++?
32 keywords are available in C++, including "int," "for," "while," and "return."
In conclusion, C++ keywords are essential language constructs with established meanings. They are essential for program structuring and flow control. In C++ programming, each of the 32 various sorts of keywords, such as "if," "class," and "return," serves a unique purpose. Understanding these keywords is critical for error-free coding. Furthermore, tokens include different aspects of C++ code such as keywords, identifiers, constants, strings, special symbols, & operators, making them the core of C++ programs.