Programming Language C++
Xulong Peng
CSC415 Programming Languages
Outline
• History
• Design, Syntax and Semantics
• Evaluation
• Code demonstration
History of C++
• C++ was developed from C
• Written by Dr. Bjarne Stroustrup from Bell
Labs in 1979
• “C and classes” and then named C++
• Standardized by ISO in 1998.
C++98, C++03, C++11 and C++14
• New features: OOP, addition safety, operator
overloading, templates, exception handling
Name, Binding and Scopes
• Name(Identifiers)
Letter, digits and underscore
case-sensitive
Keywords(i.e. int, while, using, for, namespace)
• Binding
Static binding and dynamic binding
C++ supports OOP and implements dynamic binding
Name, Binding and Scopes (continues)
• C++’s scopes
 Local scope
 Class scope
 Namespace scope
 Global scope
Data Type (C++ is a typed language)
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numeric types (integer, floating and double)
Boolean (true and false)
character
void type
pointer (*pt)
array
User-defined (struct, enum, class)
Data Type Conversion
• Narrowing conversion (double -> float)
• Widening conversion (int -> float)
• Implicit or explicit conversion
Expression and Assignment Statements
• C++ provides a rich set of operators
 unary, binary and ternary operators
++, --, +, - and ? :
 support % operator (only apply to integer)
 relational operators
• operator associativity and precedence
Associativity and Precedence
(source: Deitel and Deitel, 2012)
Assignment Statements
• Expression
int count = 10;
• Compound statements
One or more individual statements in {}
• Control statements
If …else, loop and switch
Control Structure
• Sequence Statement
• Selection Statement
• Iterative (or loop) Statement
• C++ provides break, continue, goto and return to
alter the flow of control
Selection Statements
• Selection statements offer a choice between
two or more execution.
If statement
If…else statement
Switch statement
Repetition Statements
• for (counter init; condition; counter update)
• While (condition expression){statements}
• do { statements to execute} while (condition);
• C++11 also provide a rang-based for loop
http://en.cppreference.com/w/cpp/language/range-for
Functions
• C++ uses prototype as a function declaration
• Function definition:
typeName functionName (parameter list)
{ statements; return;}
Functions
• C++ parameters can be passed by:
value, reference or const-reference
Example: double avg (const vector<int> & arr, int n, bool &
errorFlag);
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An inline function to speed up execution
Function overloading
template<template parameters>
C++’s OOP features
• Encapsulation
 Supports build-in data type and user-define ADT(class)
• Inheritance
 Provides single and multiple inheritance
• Polymorphism
 Supports dynamic binding
Exception Handling
• try … catch block
• In C++, an exception is either a user or a
library defined class
• Must be explicitly raised using throw
Concurrency
• Original C++ standard only supports single
thread programming
• C++11 adds concurrency in the form of C++11
model
• C++11 uses a thread library for starting and
managing threads
Evaluation of C++
• Readability
C++ is a large language which complicates its
readability
User defined operator overloading (aids and harms)
Supports numeric as Boolean expression affects
readability.
Case sensitive, good control structures, more flexible
iteration statements helps readability
Use of OOP improves its readability and writability
Evaluation of C++
• Writability
Its writability is highly associated with its readability
C++ has rich data type and supports abstraction
improves writability
Efficient expression helps writability
Flexible and efficient control statements
C++’s template improves writability
Evaluation of C++
• Reliability
It is reliable if used carefully
flexibility and efficiency vs. reliability (not strongly
typed and does not have strict type checking)
The use of pointer type is very flexible but could cause
dangling pointer and memory leaking
Abstraction and information hiding improves its
reliability
Exception handling improves its reliability
Evaluation of C++
• Cost
 Hard to learn as it is a large language.
 The cost of writing C++ depends on applications. Generally,
it is easy to write as syntax is very straightforward.
 Backward compatible with C (low cost for C programmer)
 Cheaper or free IDE reduces cost for training
 Inexpensive compliers decrease the cost of compilation
and execution
 Flexibility and efficiency speed up execution
 The cost on reliability and maintenance with trade-offs.
Some Code Examples
Shape
2D
Circle
3D
Square
Sphere
Cube
Q&A