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A string may be assigned in a declaration to either a character array or a variable of type char *. The declarations

char color[] = “blue”;

char* colorPtr = “blue”;

each initialize a variable to the string “blue”. The first declaration creates a 5-element array color containing the characters ‘b’, ‘l’, ‘u’, ‘e’ and ‘\0’. The second declaration creates pointer variable colorPtr that points to the string “blue” somewhere in the memory.

The first declaration determines the size of the array automatically based on the number of initializers provided in the initializer list.

Example

/* Printing a string one character at a time using a non-constant pointer to constant data */

#include<iostream.h>

int main( )

{

char strng[] = “Adams”;

char *sPtr;

sPtr =&strng[0];

cout<<“\nThe string is: \n”;

for( ; *sPtr != ‘\0’; sPtr++)

cout<<*sPtr<<‘ ‘;

return 0;

}

The output of the above program:

The string is:

A d a m s

Note: The name of a string by itself is equivalent to the base address of that string.

Passing structures as parameters

Complete copies of all members of a structure can be passed to a function by including the name of the structure as an argument to the called function.

Example

#include<iostream.h>

struct Employee // declare a global type

{

int idNum;

double payRate;

double hours;

};

double calcNet(Employee); // function prototype

int main()

{

Employee emp = {6782, 8.93, 40.5};

double netPay;

netPay = calcNet(emp); // pass by value

cout<<"The net pay for employee "

<<emp.idNum<<" is $"<<netPay<<endl;

return 0;

}

double calcNet(Employee temp) // temp is of data

// type Employee

{

return (temp.payRate * temp.hours);

}

The output is:

The net pay for employee 6782 is $361.665

In the above program, the function call

calcNet(emp);

passes a copy of the complete emp structure to the function calcNet( ). The parameter passing mechanism here is call-by-value.

An alternative to the pass-by-value function call, we can pass a structure by passing a pointer . The following example shows how to pass a structure by passing a pointer.

Example

#include<iostream.h>

struct Employee // declare a global type

{

int idNum;

double payRate;

double hours;

};

double calcNet(Employee *); //function prototype

int main()

{

Employee emp = {6782, 8.93, 40.5};

double netPay;

netPay = calcNet(&emp); // pass an address

cout<<"The net pay for employee "

<<emp.idNum<<" is $"<<netPay<<endl;

return 0;

}

double calcNet(Employee* pt) //pt is a pointer

{ //to a structure of Employee type

return (pt->payRate * pt->hours);

}

The output is:

The net pay for employee 6782 is $361.665

The typedef declaration statement

The typedef declaration statement permits us to construct alternate names for an existing C++ data type name. The syntax of a typedef statement is:

typedef data-type new-type-name

For example, the statement:

typedef float REAL;

make the name REAL a synonym for float. The name REAL can now be used in place of the term float anywhere in the program after the synonym has been declared.

The definition

REAL val;

is equivalent to

float val;

Example: Consider the following statement:

typedef struct

{

char name[20];

int idNum;

} EMPREC;

The declaration

EMPREC employee[75];

is equivalent to

struct

{

char name[20];

int idNum;

} employee[75];

Example: Consider the following statement:

typedef double* DPTR;

The declaration:

DPTR pointer1;

is equivalent to

double* pointer1;

Questions & Answers

how can chip be made from sand
Eke Reply
are nano particles real
Missy Reply
yeah
Joseph
Hello, if I study Physics teacher in bachelor, can I study Nanotechnology in master?
Lale Reply
no can't
Lohitha
where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
has a lot of application modern world
Kamaluddeen
yes
narayan
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Programming fundamentals in c++. OpenStax CNX. Jul 29, 2009 Download for free at http://cnx.org/content/col10788/1.1
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