CODEWITHSUNDEEP
c
user7926701
user7926701

Reputation:

Print float with actual float size

Im trying to print out a format of lets say x levels of accuracy meaning it should print if x = 10

float foo;
printf("levels of accuracy %.10f", foo);

What i've tried: I already have the math to convert the x to the desired decimal place. something like..

int multiplier = 10;
float initialaccuracy = 1.0;
float threshold = initialaccuracy / ((float)(pow(multiplier, accuracy)));

What I want to know:

How do i use the format of that x into the printf so if i pick x= 4 it would be %.4f or if i pick 15 it would be %.15f, without hardcoding those values just using it of whatever i pass in?

Upvotes: 1

Views: 51

Answers (2)

ChuckCottrill
ChuckCottrill

Reputation: 4444

Or, build your format string 'on the fly'...

char fmt[99];
sprintf(fmt,"levels of accuracy %%.%df",accuracy);
printf(fmt,foo);

Upvotes: 0

dbush
dbush

Reputation: 225342

You can put a * in place of the precision specifier and pass it as a separate parameter:

int accuracy = 10;
printf("levels of accuracy %.*f", accuracy, foo);

Upvotes: 3

Related Questions