CS201 Short Notes 3

*CS201 SHORT NOTES*

#includes:

The #include directive instructs the preprocessor to read and include a file into a source code file. The file name is typically enclosed with < and > if the file is a system provided file, or in quotes if the file is user provided.

Abstract class:

A class that can only be used as a base class for some other class. A class is abstract if it has at least one pure virtual function.

Aggregate:

An array or object of a class with no constructors, no private or protected members, no base classes, and no virtual functions. Also see initializer and initialization.

Alias:

Defining an alias for a structure or built-in type allows use of the alias as if it were a new type. In C, the keyword is typedef. It's a bad idea to alias (have two objects pointing to the same data) unless one of those objects is a temporary variable.

Allocation:

The process of giving memory space to an object. Also see dynamic storage, static storage, and deallocation

Argument:

When calling a function, refers to the actual values passed to the function. Also see parameter.

Array:

An ordered and indexable sequence of values. C++ supports arrays of a single dimension (a vector) or of multiple dimensions.

Assignment:

The process of giving a value to a pre-existing object. Also see copy constructor and initialization.

Base class:

A class that serves as a base for a derived class to inherit members from. Also see inheritance.

Bit:

A bit is the smallest unit of memory that can be manipulated. It has a binary or boolean value of 0 or 1. Within memory bits are combined to form bytes and words. Depending on its type, a variable in a program is stored in some number of bytes.

Bool:

C++ keyword used to declare a Boolean data type.

Break:

C++ keyword used to specify a statement that is used to break out of a for or while loop or out of a switch statement.

Byte:

A byte is a grouping of eight bits which a computer typically groups as one logical unit. It is usually the smallest addressable unit of memory.

Call by reference:

Passing a pointer to an argument to a function. The function can then change the argument value. Also see call by value.

Call by value:

Passing a copy of an argument to a function. The function cannot then change the argument value. C and C++ use call by value argument passing. But also see pointer and reference, also see call by reference.

Case:

A C++ keyword used to denote an individual element of a switch statement.

Char:

A C++ keyword used to declare an object of character type. Often considered the same as a byte, though it is possible to have multi-byte characters.

cin:

In C++ stream I/O, the standard input stream.

Class:

A C++ keyword used to declare the fundamental building block of C++ programs. A class has a tag, members, access control mechanisms, and so on.

Class layout:

The way in which data class members are arranged in a class object

Class member:

A constituent member of a class, such as a data declaration, a function, or a nested class.

Class template:

A template used for generating class types.

Comments:

C++ has C-style comments delimited with /* and */, and new C++-style line-oriented comments starting with //.

Compiler:

A software tool that converts a language such as C++ into a different form, typically assembly language.

Const:

A C++ keyword used to declare an object as constant or used to declare a constant parameter.

Constructor:

A function called when a class object comes into scope. The constructor is used to initialize the object. See allocation, copy constructor, and destructor.

Continue:

C++ keyword used with for and while statements to continue the iteration at the top of the loop.

Copy constructor:

A special type of constructor that is called when an object is copied.

cout:

In C++ stream I/O, the standard output stream.

Data structure:

The term data structure refers to the way data is organized for use within a program. Correct organization of data can lead to simpler and more efficient algorithms. Common data structures are linked-lists, stacks, queues and trees.

Debugger:

A tool for stepping through the execution of a program, examining variables, setting breakpoints, and so on.

Declaration:

A C++ entity that introduces one or more names into a program. declaration specifies to the compiler the types of all the elements of an identifier; "this function or this piece of data exists somewhere else, and here is what it should look like." See also definition for definition.

Default argument:

An optional argument to a function. A value specified in the function declaration is used if the argument is not given.

Definition:

Instantiates an identifier, allocating its memory. A declaration can also be a definition. You can declare data or a function in many difference places, but can define it only once.

Delete operator:

C++ keyword and operator used to delete dynamic storage.

Derived class:

A class that inherits members from a base class.

Destructor:

A function called when a class object goes out of scope. It cleans up the object, freeing resources like dynamic storage.

Do:

A C/C++ reserved word that allows construction of an iterative loop. The statements in the body always execute at least once. Also see while.

Double:

A fundamental data type in C and C++. Double variables are used to store floating-point values. They offer greater precision and can store larger numbers than floats.

Dynamic memory allocation:

The process of dynamically creating objects in the heap or free store during program runtime. Statically created objects, created by the compiler, are put on the program stack.

Else:

C++ keyword, part of the if statement, that allows conditional execution of code.

endl:

The standard C++ library provides a set of manipulator functions that can modify the state of iostream objects. endl writes a new line to output.