C Format Specifier

C Format Specifier:

    The format specifiers are used in C for input and output purposes. Using this concept the compiler can understand that what type of data is in a variable during taking input using the scanf() function and printing using printf() function. Here is a list of format specifiers.

    The Format specifier is a string used in the formatted input and output functions. The format string determines the format of the input and output. The format string always starts with a '%' character.

The commonly used format specifiers in printf() function are:

Format specifier	Description
%u	It is used to print the unsigned integer value where the unsigned integer means that the variable can hold only positive value.
%d or %i	It is used to print the signed integer value where signed integer means that the variable can hold both positive and negative values.
%x	a hexadecimal (base 16) integer
%o	It is used to print the octal unsigned integer where octal integer value always starts with a 0 value.
%X	It is used to print the hexadecimal unsigned integer, but %X prints the alphabetical characters in uppercase such as A, B, C, etc.
%hi	short (signed)
%hu	short (unsigned)
%Lf	long double
%n	prints nothing
%i	a decimal integer (detects the base automatically)
%p	an address (or pointer)
%e	a floating point number in scientific notation

 

Let's understand the format specifiers in detail through an example.

%d:

we are printing the integer value of b and c by using the %d specifier.

int main()

{

  int a=60;

  int b=10;

  printf("Value of b is:%d", b);

  printf("\nValue of c is:%d",c);

    return 0;

}

%u:

we are displaying the value of b and c by using an unsigned format specifier, i.e., %u. The value of b is positive, so %u specifier prints the exact value of b, but it does not print the value of c as c contains the negative value.

int main()

{

  int a=20;

  int b= -80;

  printf("Value of b is:%u", b);

  printf("\nValue of c is:%u",c);

    return 0;

}

%x and %X:

y contains the hexadecimal value 'A'. We display the hexadecimal value of y in two formats. We use %x and %X to print the hexadecimal value where %x displays the value in small letters, i.e., 'a' and %X displays the value in a capital letter

int main()

{

  int y=0xA;

  printf("Hexadecimal value of y is: %x", y);

  printf("\nHexadecimal value of y is: %X",y);

  printf("\nInteger value of y is: %d",y);

    return 0;

}

%f:

The above code prints the floating value of y.

int main()

{

  float y=22.7;

  printf("Floating point value of y is: %f", y);

  return 0;

}