Dynamic Float Format Specifier in C

问题

Is there any way to have a user inputed float format specifier? For example, if I print this.

float c = 15.0123
printf("%.2f", c);

// outputs: 15.01

How can I assign the number of decimal places to a variable? Like:

int n = 3;
float c = 15.0123
printf("%.(%i)f", n, c);

// outputs: 15.012

回答1:

The precision can be specified by an argument with the asterisk *. This is called an argument-supplied precision.

float c = 15.0123;
int m = 2;
printf("%.*f", m,  c);

回答2:

printf("%.*f", n, c); that will print out c with n places after the decimal.

来源：https://stackoverflow.com/questions/9627075/dynamic-float-format-specifier-in-c