Console I/O Operations:

The printf() Function: This function is most versatile way to display output on screen. When using printf(), you
need to include the standard input/output header file, STDIO.H.

int printf(format-string [,arguments,…]);

Format string can have: Literaltext, conversionspecifier, escapesequences.
The format-string is required; however, arguments are optional.
For each argument, there must be a conversion specifier.

We can provide optional specifier as field width.
For Ex.

• printf(“%10d”,456) .It means print the variable as decimal integer in the field of 10 columns.
• printf(“%10.2f “,405.3405)here 10 is for columns and 2 is for digits displayed after decimal point

Specifiers	Type Converted
%c	char
%d	int,short
%ld	Long
%f	float
%s	char arrays
%u	unsigned int, unsigned short
%lu	unsigned long

scanf() Function

scanf(“format string”, list of addresses of variables);

• The scanf() function reads data from the keyboard according to a specified format and assigns the input data to one or more program variables.
• Like printf(), scanf() uses a format string to describe the format of the input. The format string utilizes the same conversion specifiers as the printf() function.
• A single scanf() can input more than one value if you include multiple conversion specifiers in the format string and variable names (again, each preceded by & in the argument list).
• The & symbol is C’s address-of operator

The following statement inputs an integer value and a floating-point value and assigns them to the variables x and rate, respectively:
scanf(“%d %f”, &x, &rate);

• When multiple variables are entered, scanf() uses white space to separate input into fields. White space can be spaces, tabs, or new lines.
• Each conversion specifier in the scanf() format string is matched with an input field; the end of each input field is identified by white space.
• The reading will be terminated, when scanf encounters an invalid mismatch of data or character that is not valid for value being read.
• An unread data item in a line will be considered as part of the data input to the next scanf call.