Formatted input/output function in Turbo C Language

It is very easy to use unformatted input/output functions as discussed. We can read and display only characters not numbers using unformatted functions. Using formatted input/output functions, we can read integers, floating point number and characters. The formatted input function is scanf() and formatted output functions is printf().

Scanf()

Syntax
int scanf(“format string”, &var1, &var2, &var3,……..&varn);

This function scanf() is used to read any type of data such as int, char, float, double and even string from the keyboard. It accepts the following two parameters:
• format string consists of one or more format specifires starts with % symbol.
• &var1, &var2, &var3, …., &varn represents the list of variables. Here, symbol ‘&’ refers to the address of the variable. In the memory locations identified by these addresses, the respective values are stored.
Return Type int: The function returns an integer value. This integer value is the number of item that have been read successfully using the keyboard. But, we rarely use this return value in our programs.
The various format specifiers along with the associated meaning are shown in the following table:

Data Type	Format Specifier	Meaning
int	%d %o %x %i %u %h	Read a decimal integer value Read an octal value Read a hexadecimal value Read a decimal, octal or hexadecimal value Read an unsigned integer value Read a short integer value
float	%e %f %g	Read a floating point number Read a floating point number Read a floating point number
char	%c %s	Read a character Read a string (series of character)
double	%f	Read a long floating point number or double
long int	%ld	Read a long integer value

The following table shows the way the user has to enter the values from the keyboard:

Input statement	Entering value	Input way
scanf(“%d%d%d”,&a,&b,&c);	3 integer value	10 20 30 Where, a=10      b=20       c=30
scanf(“%d,%d,%d”,&a,&b,&c);	3 integer value	10,20,30 Where, a=10      b=20       c=30
scanf(“%f”,&a);	1 floating point value	787.35 Where, a=787.3.5
scanf(“%c”,&a);	1 character value	P Where, a=p
scanf(“%f,%d,%c”,&a,&b,&c);	1 floating point value 1 integer value 1 character value	787.35 10 P Where, a=787.35, b=10, c=P
scanf(“%d-%d-%d”,&a,&b,&c);	3 integer values separated by ‘-‘ (hyphen) sign	10-20-30 Where, a=10, b=20, c=30
scanf(“%d%d%d”,&a,&b,&c);	3 integer values separated by ‘/’ (slash) symbol	10/20/30 Where, a=10, b=20, c=30

Note: Do not use any escape sequences such as \t, \n etc. in scanf().

For example: Consider the following statement:
scanf(“%d\n”,&a);
In the above statement, remove ‘\n’, otherwise it may give wrong output.
Now, let us see, some more ways of data reading using scanf() function are given below:

Input statement	Entering value	Input way
scanf(“%2d%2d%2d”,&a,&b,&c);	3 integer values	1 2 3 Where, a=1  b=2  c=3
		11 22 33 Where, a=11  b=22  c=33
		102030 Where, a=10  b=20  c=30
		102 030 4 Where, a=10  b=2  c=3 The remaining two digits 0 and 4 are ignored or can be read by a subsequent scanf()
scanf(“%12s”,&str);	1 string	.Programming Where, str=.Programming
scanf(“%[^\n]s”,str);	Input the string till the end of line	Wlecome! To the dotprogramming Where, str= Wlecome! To the dotprogramming

Note:
• To read a string with space gets() function will used in place of scanf().
• The “scanf(“%[^\n]s”,str);” function read and stored all the character untill user will not press enter key.

Formatted Output Function