C how does printf work

The answer is vararg. We demonstrate this by an average function that will accept any number of arguments. Example of using Vararg for average function is as follows:.

User supply a string and input arguments. Minimum number of characters to be printed. If the value to be printed is shorter than this number, the result is padded with blank spaces. The value is not truncated even if the result is larger. The width is not specified in the format string, but as an additional integer value argument preceding the argument that has to be formatted.

If the value to be written is shorter than this number, the result is padded with leading zeros. The value is not truncated even if the result is longer.

A precision of 0 means that no character is written for the value 0. By default all characters are printed until the ending null character is encountered. Does ES6 make JavaScript frameworks obsolete? Podcast Do polyglots have an edge when it comes to mastering programming Featured on Meta. Now live: A fully responsive profile. Linked 6. Related Hot Network Questions.

Stack Overflow works best with JavaScript enabled. Accept all cookies Customize settings. Once we found it, we check the next character. This is the formatting character. Formatting character says how to format the argument to visible output string. Printf supports varieties of formatting. C is for character, d for decimal integer, f for floating point, x for hexadecimal and s for strings.

Argument variable is then converted to string format and appends to the output string. C itoa function has been used to convert argument integer to string. Visit our topic integer to string conversion for further understanding. This process of coping characters and conversion of arguments repeats until the string is terminated to last NULL character. For simplicity we have implemented only c, d, x formatting cases. Now at the end we have the output string ready.

This is now passed to fwrite to stdout. Thus the output string prints in the actual console. Printf then returns the number of characters which is printed in the console and exit the function. It converts the scanned string to variables and copies to the output variables. Scanf is reverse process of printf.

Scanf reads console input string.