The document discusses various C++ concepts related to pointers and the standard template library (STL). It explains pointers to functions, arrays of pointers, pointers to pointers, and the scope resolution operator. It also provides background on the C++ standard library and STL, noting that the STL provides containers, iterators, algorithms, and functors and was originally published by Silicon Graphics and included in the C++ standard.

1. Pointers to functions
09/04/131 VIT - SCSE
Functions to be referenced by a pointer
return_type (*variable)(list of parameters);
for example,
float (*p)(float,float,float);
p=&average;

2. 09/04/132 VIT - SCSE
#include<iostream.h>
#include<conio.h>
void main()
{
float average(float x,float y, float z);
float a,b,c,avg;
float (*p)(float x,float y,floatz);
p=&average;
cout<<”Enter three numbers”;
cin>>a>>b>>c;
avg=(*p)(a,b,c);
cout<<”Average=”<<avg;
getch();
}
float average(float x,float
y,floatz)
{
float temp;
temp=(x+y+z)/3.0;
return(temp);
}

3. Pointers and Arrays
09/04/133 VIT - SCSE
int value[5]={2,5,1,6,3};
int *p;
p=value; (take the address of 0th
location)
//p=&value[2]; (ok)
cout<<p;
cout<<*p;

4. Arrays of Pointers
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Int *p[3];
i.e p[0], p[1], p[2]
int a=4;
int b=6;
int c=2;
int *p[3];
p[0]=&a;
p[1]=&b;
p[2]=&c;
cout<<*p[0];
cout<<*p[1];
cout<<*p[2];
cout<<p[0];
cout<<p[1];
cout<<p[2];

5. Pointers to Pointers
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Int a;
Int *p;
Int **q;

6. 09/04/136 VIT - SCSE
#include<iostream.h>
void main()
{
int value;
int *p;
int **q;
value=100;
cout<<”value=”<<value<<endl;
p=&value;
q=&p;
cout<<”Pointer 1=”<<*p<<endl;
cout<<”Pointer 2=”<<**q<<endl;
}

7. Scope Resolution Operator
::variablename;
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#include<iostream.h>
int m=10; //global
int main()
{
int m=20; //local to main
{ int k=m;
int m=30;
cout<<”we are in inner block”<<endl;
cout<<”k=”<<k<<endl;
cout<<”m=”<<m<<endl;
cout<<”::m=”<<::m<<endl;
} return 0;
}

8. Standard Template Library (STL
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It is a software library partially included in the C++ Standard
Library.
It provides containers, iterators, algorithms, and functors.
More specifically, the C++ Standard Library is based on the
STL published by SGI.
(Silicon Graphics Computer Systems or SGCS) was a
manufacturer of high-performance computing solutions,
including computer hardware and software, founded in 1981
by Jim Clark and Abbey Silverstone.

9. 09/04/139 VIT - SCSE
C++ Standard Library
ios
iostream
iomanip
fstream
sstream
Standard Template Library
vector
deque
list
map
set
stack
Queue
Vector is a class template in the C++ Standard Template
Library, which functions like a dynamic array.

10. 09/04/139 VIT - SCSE
C++ Standard Library
ios
iostream
iomanip
fstream
sstream
Standard Template Library
vector
deque
list
map
set
stack
Queue
Vector is a class template in the C++ Standard Template
Library, which functions like a dynamic array.