History
• C (1969) C++ (1979) Java (1995)
• Both support OOP.
Most OOP library contents are similar, however Java continues to grow.
• Syntax is very close – Java has strong influence of C/C++.
Easy to learn the other language when you know one of these.
C++ compiler & Linker usage
Java compiler usage
C++ vs. Java: differences
C++ vs. Java: differences …
C++ vs. Java: differences …
C++ Java
Explicit memory management.
Supports destructors. Automatic Garbage Collection. Supports operator overloading. Specifically operator overloading was thrown out.
Types of memory used by executable task
Code Stack data (static) heap (dynamic)
Objects
• Objects can be created as local variables just like any basic data types in C++.
C++:
ComplexType num1;
Java: Nothing equivalent – Objects cannot be in stack.
Objects in Heap
C++:
ComplexType *num1 = new ComplexType(…);
Java:
ComplexType num1 = new ComplexType(…);
Arrays
• Basic data types and classes are treated the same way in C++, unlike Java.
C++: ComplexNumber numbers[5];
Java: nothing equivalent.
C++ array version #2
ComplexNumber *numbers;
numbers = new ComplexNumber[5];
Java: nothing equivalent for classes, but possible for basic data types:
int numbers[];
numbers = new int[5];
C++ array version #3
ComplexNumber **numbers;
numbers = new ComplexNumber*[5];
for( index i = 0 ; i < 5 ; i++)
numbers[i] = new ComplexNumber(…);
Java:
ComplexNumber numbers[];
numbers = new ComplexNumber [5];
for( index i = 0 ; i < 5 ; i++)
numbers[i] = new ComplexNumber(…);
C++ vs. Java: Analogy
• Working with C++ is like flying a airpline, while working with Java is like driving a car.
• What does it mean?
• Too many controls/options in C++: think before use each one.
• Careful use can result in efficiency, poor use can result in serious inefficiency
• Issues like memory leak can crash the application, out-of-bounds array access can cause memory corruption – but it may not show up for long time – causing lot of headache!
• Java : slow and steady wins the race?