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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

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
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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