What you should know about C++

What you should know about C++

Comparison to Java

C++                                                            

class IntStack {           

public:

IntStack(int max=100);

~IntStack();

void push(int);

int pop();

protected:

int * stack;

int top;

public:

int size();

};

JAVA

class IntStack {

public IntStack(int max) {

stack = new int[max];

top = -1;

}

protected void finalize() {

// nothing to do here

}

public void push(int k) {

stack[++top] = k;

}

// ...

protected int [] stack;

protected int top;

};

new and delete operators

• new operator similar to Java

• new and delete in C++ return explicit pointers.

• Java: int[] A = new int[3];

• C++: int * A = new int[3];

• C++: Node * n = new Node;

• In Java, there’s garbage collection. In C++, have to delete

explicitly:

• C++: delete [] A;

• C++: delete myStack

Classes – Example use

• Stored as a local variable:

{

IntStack S(10000);

S.push(10);

S.push(12);

} // ~InStack automatically called

• Stored on heap:

{

IntStack * S = new IntStack(10000);

S->push(10);

S->push(12);

delete S;

}.........

What you should know about C++