Format specifiers in C are special characters that are used in formatted input and output operations. They tell the functions like printf() and scanf() how to format the data that is being printed or read. Here are some of the most commonly used format specifiers in C:
- %d – format specifier for signed integers.
- %u – format specifier for unsigned integers.
- %f – format specifier for floating-point numbers.
- %c – format specifier for single characters.
- %s – format specifier for null-terminated strings.
- %p – format specifier for pointers.
- %x or %X – format specifier for hexadecimal numbers.
- %o – format specifier for octal numbers.
In addition to these basic format specifiers, C also provides several options to control the width, precision, and alignment of the output. These options are specified using the following syntax:
- %n.mspecifier – Here, “n” is the minimum field width, “m” is the precision, and “specifier” is the format specifier. For example, the format specifier %5.2f would print a floating-point number with a minimum width of 5 characters, and 2 digits after the decimal point.
Here are some additional format specifier options:
- %-n.mspecifier – Left-justified version of the specifier, with a minimum width of “n” and “m” digits after the decimal point.
- %*specifier – The width of the output is specified by an integer argument instead of a literal value. For example, printf(“%*d”, 5, 10) would print the integer 10 with a minimum width of 5 characters.
In general, understanding format specifiers in C is essential for working with formatted input and output functions, and it’s important to use them correctly to avoid issues with data type conversion, buffer overflow, and other common programming errors.