CPP Language / Iostream Library Classes
| Class Name |
Details |
| ios class |
It is used to read and write input a sequence of characters. |
| istream Class |
It is used to read input as a sequence of characters by cin statement. |
| ostream class |
It is used to write a sequence of characters by cout statement. |
Formatted I/O Function
Types of I/O Functions
| No.
|
Types of functions |
Details
|
| 1 |
Input functions
|
It reads the input from the keyboard, file and network program< |
| 2 |
Output functions |
It writes the output to console, file and network program |
Types Of Input/output Functions
| No.
|
Functions
|
Details
|
| 1
|
Formatted input/output functions. |
Used for performing input/output operations at console and the resulting data is formatted
|
| 2 |
Unformatted input/output functions. |
Used for performing input/output operations at console and the resulting data is unformatted |
Unformatted Input/output Functions
| No.
|
Functions
|
Description
|
| 1
|
get(char *)
|
It is used to read a single character from user console.
|
| 2
|
get()
|
It is used to read a single character from user console and returns it.
|
| 3
|
getline(char* arr, int size)
|
It is used to Read a line of characters from user console.
|
| 4
|
put(char ch)
|
It is used to write a single character at user console.
|
| 5
|
write(char *arr, int num)
|
It is used to write a character array at user console.
|
Formatted Console Input/output Functions
| Functions
|
Method Description
|
| width(int width)
|
It is used to set the width of a value to be displayed in the output.
|
| precision()
|
It is used to set the number of the decimal point to a float value.
|
| fill()
|
It is used to set a character to fill in the blank space of a field
|
| setf()
|
It is used to set various flags for formatting output
|
| unsetf()
|
It is used to remove the flag setting
|
Formatted Console Input/output Functions Example
| Program |
Output |
#include
using namespace std;
void width()
{
cout << "Implementing width\n";
char c = 'W';
cout.width(4); // Adjusting width to 4.
cout << c <<"\n\n";
}
void precision()
{
cout << "Implementing precision\n";
cout.setf(ios::fixed, ios::floatfield);
cout.precision(2);
cout<<2.1234<<"\n\n";
}
void fill()
{
cout << "Implementing fill\n";
char c = 'W';
cout.fill('*');
cout.width(5);
cout<
}
void setf()
{
cout << "Implementing setf\n";
int n=100;
cout.setf(ios::showpos);
cout<
}
void unsetf()
{
cout << "Implementing unsetf\n";
cout.setf(ios::showpos|ios::showpoint);
cout.unsetf(ios::showpos);
cout<<400.0<<"\n\n";
}
int main()
{
width();
precision();
fill();
setf();
unsetf();
return 0;
}
|
Implementing width
W
Implementing precision
2.12
Implementing fill
****W
Implementing setf
+100
Implementing unsetf
400.00
|
|