Explain the different types of input and output statements used in C.
C support many input and output
statements. It also supports formatted input and output.
Basic Character Input &
Output:
getchar() function: It reads one
character from the standard input. If there is no more characters available,
the special value EOF will be return.
Example: char c;
….
c=getchar();
putchar() function: It writes one
character to the standard output (Monitor).
Example: char
c;
c=”A”;
putchar(c);
Formatted Input:
Input data can be entered into the
computer from a standard input device by means of the standard C library
function scanf(). This function can be used to enter any combination of
numerical values, single character and strings. The function returns the number
of data items that have been entered successfully.
Syntax: scanf( control string, arg1, arg2,….argn)
The control string consist of control
characters, whitespace characters and nor-whitespace characters. The control
characters are preceded by a % sign and are listed below.
|
Control Character
|
Explanation
|
|
%c
|
A
single character
|
|
%d
|
A
decimal integer
|
|
%i
|
An
integer
|
|
%e,
%f, %g
|
A
floating-point number
|
|
%o
|
An
octal number
|
|
%s
|
A
string
|
|
%x
|
A
hexadecimal number
|
|
%p
|
A
pointer
|
|
%n
|
An
integer equal to the number of characters read so far
|
|
%u
|
An
unsigned integer
|
|
%[]
|
A
set of characters
|
|
%%
|
A
percent sign
|
Example: int i;
float
f;
char
c;
char
str[10];
scanf(“%d
%f %c %s”,&I,&f,&c,str);
Formatted Output:
Output data can be written from the
computer onto a standard output device using the library function printf(). This function can be used to output
any combination of numerical values, single characters and strings. It similar
to the input function scanf(), except that its purpose is to display data
rather than enter into the computer.
Syntax: printf(control string, arg1,
arg2, ….argn)
The control string characters are listed
above (same as input control string)
Example: printf(“%d %o %x\n”,
100,100,100);
Will
print : 100 144 64
Printf(“%c
%d %f %e %s %d%%\n”,’3’,4,3.24,66000000,”nine”,8);
Will print : 3 4
3.240000 6.600000e+7 nine 8%