Precision modifier as a variable in C

Question

In my program the user inputs the number of decimal places he requires in an output. I save this input as deci. How do I use this variable deci as a precision modifier?

Sample: Input a number: 23.6788766 Input number of decimals: 2 Output: 23.67

Answer 1

If it is C you can do:

float floatnumbervalue = 42.3456;
int numberofdecimals = 2;
printf("%.*f", numberofdecimals, floatnumbervalue);

Answer 2

In C, for example to change the default precision of 6 digits to 8:

int precision = 8;

printf("%.*f\n", precision, 1.23456789);

The precision argument has to be of type int.