I am asking a user for two non-negative integer values in C. I then want to convert these to percentages (expressed as decimals). Unfortunately, my float
s are coming up as zeroes. Why is this, and how do I fix it?
int a = 5;
int b = 10;
int total = a + b;
float a_percent = a / total;
float b_percent = b / total;
printf("%.2f, %.2f\n", a_percent, b_percent);
You aren't using floats, you're using integers, and so the integral division gives zero (which is then assigned to a float).
To perform a floating-point operation, you must first convert the integers (or at least one of them) to a float. Conveniently, we just use total
:
float total = a + b; // exact
float ap = a / total;
float bp = b / total; // OK, these are now floating-point operations
除了其他人指出的问题外,该比率直到您乘以100.0才算是百分比。
An int
divided by an int
will always return an int
. You'll have to make one of the two arguments a float
before dividing:
float a_percent = (float) a / total;
float b_percent = (float) b / total;
I am not a C expert, but my guess is because dividing an int by an int always results in an int.
You may need to do something like this:
float a_percent = (float)a/total;
float b_percent = (float)b/total;
You're first performing an integer division, then converting the result to floating point. This will not give the results you want. Either make total
a floating point value to begin with (so that the types get automatically promoted right) or cast a
and b
to (float)
before performing the division.
You are using integer math not floating point here. Try:
float a_percent = a/(float)total;
float b_percent = b/(float)total;
For a simple percentage you may be happier using fixed-point. Just multiply your numerator (a or b) by 100 and you'll get the percentage from the division. forex:
int a = 5;
int b = 10;
int total = a + b;
int a_percent = 100*a/total;
int b_percent = 100*b/total;
printf("a%%=%d, b%%=d\n", a_percent, b_percent);
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.