quick guide

Commonly Used scanf() Formates in C language:

code Meaning
%d - Read a decimal integer

%e - Read a floating point value

%f - Read a floating point value

%g - Read a floating point value

%h - Read a short integer

%i - Read a decimal,hexadecimal or
octal integer

%o - Read an octal integer

%s - Read a string

%u - Read an unsigned decimal integer

%c - Read a single character

%x - Read a hexadecimal integer

%[....] - Read a string of word[s]

Points to remember while using scanf:
If we do not plan carefully,some crazy things can
happen with scanf.Since the i/o routines are not a part
of c language,they are made available either as a
separate module of the c library or as a part of the
operating system(like unix).Givenbelow are some of the
general points to keep in mind while writing a scanf
statement.

1.All function arguments,except the control string,must
be pointers to variables.
2.Format specifications contained in the control string
should match the arguments in order.
3.Input data items must be separated by spaces and must
match the variables receiving the input in the same
order.
4.The reading will be terminated,when scanf encounter an
invalid
mismatch of data or a character that is not
valid for the value being read.
5.When searching for a value,scanf ignores line boundar
ies and simply looks for the next appropriate character.
6.Any unread data items in a line will be considered as a
part of the data input line to the next scanf call.
7.When the field width specifier w is used,it should be
large enough to contain the input data size.

Formatted Output: The printf statement provides certain
features that can be effectively exploited to control the
alignment and pacing of print-outs n the terminals. The
general form of printf statement is
printf("control string",arg1,arg2,.........argn);
control string consists of three of items:
1.Characters that will be printed on the screen as they
appear.
2.Format specifications that defines the output format
for display of each item.
3.Escape sequence characters such as \n,\t and \b.
The control string indicates how many arguments follow
and what their types are. The arguments arg1,arg2,........
argn are the variables whose values are formatted and
printed according to specifications of the control string.
The argument should match in number,order and type with the
format specifications.
A simple format specification has the following form:
%w.p type-specifier.
Where "w"is an integer number that specifies the total
number of columns for the output value and p is another
integer number that specifies the number of digits to the
right of the decimal point or the number of characters to
be printed from a string.
Both w and p are optional. Some examples of printf statement
are:

printf("programming in c");
printf(" ");
printf("\n");
printf("%d",x);
printf("a=%f\n b=%f",a,b);
printf("sum=%d",1234);
printf("\n\n");
printf never supplies a new line automatically and therefore
multiple printf statements may be used to build one line of
output.