What's the function of printf?

[pooria taheri]

what the function of this string....
printf("%d",pri ntf(test));

i know the result,i checked it in practices but i havent any idea about what really happended,pleas e answer me and i will owe you one ...tnx all

[weaknessforcats]

printf returns the number of characters displayed. So the outer printf displays the number of characters displayed by the inner printf.

Notice the %d on the outer printf. A %d is used to display an int. In this case the int returned by the inner printf.

This is a very common programming style.