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This tutorial series will help you to get started in C++ to develop system applications.
/*
* File: main.cpp
* Author: Nano
* Just click image to copy & paste
*/
#include <iostream>
int main() {
std::cout<<"This is my first c++ Program.";
std::cout<<std::endl<<"and its very easy";
}
$ gcc -v/*
* File: main.cpp
* Author: Gautam
* Created on October 16, 2011, 4:09 PM
*/
#include <iostream>
int main() {
std::cout<<"This is my first c++ Program.";
std::cout<<std::endl<<"and its very easy";
}
| /* Comments */ | Comments are a way of explaining what makes a program. Comments are ignored by the compiler and used by others to understand the code. |
| #include<iostream> | is a preprocessor directive. It tells the preprocessor to include the contents of iostream header file in the program before compilation. This file is required for input output statements. |
| int/void main() | int/void is a return value, which will be explained in a while. |
| main() | The main() is the main function where program execution begins. Every C++ program should contain only one main function. |
| Braces | Two curly brackets “{…}” are used to group all statements together. |
/*
* File: main.cpp
* Author: Gautam
* Created on October 16, 2011, 4:09 PM
*/
#include <iostream>
using namespace std;
int main() {
cout<<"This is my first c++ Program.";
cout<<endl<<"and its very easy";
}| return 0 | At the end of the main function returns value 0. |
Manipulators are operators used in C++ for formatting output. The data is manipulated by the programmer’s choice of display.
setw(x)/*
* File: main.cpp
* Author: Gautam
* Created on October 16, 2011, 12:58 PM
*/
#include <iostream>
#include <iomanip>
using namespace std;
int main() {
float basic, ta,da,gs;
basic=10000; ta=800; da=5000;
gs=basic+ta+da;
cout<<setw(10)<<"Basic"<<setw(10)<<basic<<endl
<<setw(10)<<"TA"<<setw(10)<<ta<<endl
<<setw(10)<<"DA"<<setw(10)<<da<<endl
<<setw(10)<<"GS"<<setw(10)<<gs<<endl;
return 0;
}| Basic | 10000 |
| TA | 800 |
| DA | 5000 |
| GS | 6800 |
/*
* File: main.cpp
* Author: Gautam
* Created on October 16, 2011, 12:58 PM
*/
#include <iostream>
#include <iomanip>
using namespace std;
int main() {
cout << setw(20) << setfill('*') << "w3schools.in" << setw(20) << setfill('*')<<"Test"<< endl;
}| Data Type (Keywords) | Description | Size | Typical Range |
|---|---|---|---|
| char | Any single character. It may include a letter, a digit, a punctuation mark, or a space. | 1 byte | -128 to 127 or 0 to 255 |
| signed char | Signed character. | 1 byte | -128 to 127 |
| unsigned char | Unsigned character. | 1 byte | 0 to 255 |
| wchar_t | Wide character. | 2 or 4 bytes | 1 wide character |
| Data Type (Keywords) | Description | Size | Typical Range |
|---|---|---|---|
| int | Integer. | 4 bytes | -2147483648 to 2147483647 |
| signed int | Signed integer. Values may be negative, positive, or zero. | 4 bytes | -2147483648 to 2147483647 |
| unsigned int | Unsigned integer. Values are always positive or zero. Never negative. | 4 bytes | 0 to 4294967295 |
| short | Short integer. | 2 bytes | -32768 to 32767 |
| signed short | Signed short integer. Values may be negative, positive, or zero. | 2 bytes | -32768 to 32767 |
| unsigned short | Unsigned short integer. Values are always positive or zero. Never negative. | 2 bytes | 0 to 65535 |
| long | Long integer. | 4 bytes | -2147483648 to 2147483647 |
| signed long | Signed long integer. Values may be negative, positive, or zero. | 4 bytes | -2147483648 to 2147483647 |
| unsigned long | Unsigned long integer. Values are always positive or zero. Never negative. | 4 bytes | 0 to 4294967295 |
| Data Type (Keywords) | Description | Size | Typical Range |
|---|---|---|---|
| float | Floating point number. There is no fixed number of digits before or after the decimal point. | 4 bytes | +/- 3.4e +/- 38 (~7 digits) |
| double | Double precision floating point number. More accurate compared to float. | 8 bytes | +/- 1.7e +/- 308 (~15 digits) |
| long double | Long double precision floating point number. | 8 bytes | +/- 1.7e +/- 308 (~15 digits) |
| Data Type (Keywords) | Description | Size | Typical Range |
|---|---|---|---|
| bool | Boolean value. It can only take one of two values: true or false. | 1 byte | true or false |
#include <iostream>
using namespace std;
int main()
{
cout << "Size of char is " << sizeof(char) << endl;
cout << "Size of int is " << sizeof(int) << endl;
cout << "Size of float is " << sizeof(float) << endl;
cout << "Size of short int is " << sizeof(short int) << endl;
cout << "Size of long int is " << sizeof(long int) << endl;
cout << "Size of double is " << sizeof(double) << endl;
cout << "Size of wchar_t is " << sizeof(wchar_t) << endl;
return 0;
}enum enum-name {list of names}var-list;enum mca(software, internet, seo);typedef [data_type] synonym;typedef [data_type] new_data_type;typedef int integer;
integer rollno;type variable_name;type variable_name, variable_name, variable_name;/* variable definition and initialization */
int width, height=5;
char letter='A';
float age, area;
double d;
/* actual initialization */
width = 10;
age = 26.5;