JAVA：没有得到我想要的小数位数

Question

I have a code where the variable "sum" is an integer. I am trying to find the average, such that

int sum = 1;
float avg = 0;

//later on in the code
avg = (float)sum/37;

According to Android Studio debugger, the value stored in avg is 0.0, and not the desired 0.02... I want more decimal points, but my answer is getting rounded up to 1 decimal place. I tried the above code with the data type "double" and I am getting the same answer. Anyone have any tips?

Answer 1

Try with:

avg = sum/37f;

Your problem is integer/integer = integer In your case the cast happens when the integer computation is done, which is to late.

Answer 2

Your problem is that operator precedence of your code resolved to:

avg = (float)(sum/37);

This means that you're still doing int / int math, which results in 0 , before the cast to float .

There are two ways to fix it:

avg = ((float)sum)/37; // cast sum to float before division
avg = sum/37f; // change to a float literal so sum is coerced to float for you