K&R C Exercise 2-3: htoi — Convert Hex String to Integer

Posted on December 21, 2011June 21, 2026 by Sandeepa Nadahalli

Exercise 2-3. Write the function htoi(s), which converts a string of hexadecimal digits (including an optional 0x or 0X) into its equivalent integer value. The allowable digits are 0 through 9, a through f, and A through F. How htoi Works Hexadecimal is simply base-16 positional notation. Converting from a hex string to an integer …

Binary to Decimal, Octal, and Hexadecimal in C – Conversion Program

Posted on October 19, 2011June 29, 2026 by Sandeepa Nadahalli

Converting a binary number to decimal, octal, and hexadecimal in C demonstrates how the same bit pattern can be expressed in different bases. Binary uses base 2, decimal uses base 10, octal uses base 8, and hexadecimal uses base 16. Once you have the decimal value, C’s printf format specifiers (%o and %X) handle octal …