java 如何将浮点数四舍五入到最近的四分之一
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How to round a float to the nearest quarter
提问by Bick
Sometimes I need to round a float to the nearest quarter and sometimes to the nearest half.
有时我需要将浮点数舍入到最近的四分之一，有时需要舍入到最近的一半。
For the half I use
对于我使用的一半
Math.round(myFloat*2)/2f
I can use
我可以用
Math.round(myFloat*4)/4f.
Math.round(myFloat*4)/4f.
but is there any other suggestions?
但还有其他建议吗？
回答by Paul Sasik
All you need is:
所有你需要的是：
Math.round(myFloat*4)/4f
Since a half is also two quarters this single equation will take care of your half-rounding as well. You don't need to do two different equations for half or quarter rounding.
由于一半也是四分之二，这个单一的等式也将处理你的半舍入。您不需要为二分之一或四分之一四舍五入做两个不同的方程。
Code Sample:
代码示例：
public class Main {
public static void main(String[] args) {
float coeff = 4f;
System.out.println(Math.round(1.10*coeff)/coeff);
System.out.println(Math.round(1.20*coeff)/coeff);
System.out.println(Math.round(1.33*coeff)/coeff);
System.out.println(Math.round(1.44*coeff)/coeff);
System.out.println(Math.round(1.55*coeff)/coeff);
System.out.println(Math.round(1.66*coeff)/coeff);
System.out.println(Math.round(1.75*coeff)/coeff);
System.out.println(Math.round(1.77*coeff)/coeff);
System.out.println(Math.round(1.88*coeff)/coeff);
System.out.println(Math.round(1.99*coeff)/coeff);
}
}
Output:
输出：
1.0
1.25
1.25
1.5
1.5
1.75
1.75
1.75
2.0
2.0
回答by chargers2143
(Math.round(num/toNearest))*toNearest;
(Math.round(num/toNearest))*toNearest;
Will round a number to toNearest
将一个数字四舍五入到 toNearest
回答by Shafique Arnab
Mathematically speaking, you could multiply your float by .25, round it, and then divide again by .25.
从数学上讲，您可以将浮点数乘以 0.25，四舍五入，然后再除以 0.25。
EDIT: I'm sorry, it seems I misunderstood what you meant by quarter. However, as far as I know, this is the simplest way to round to various decimal places and degrees.
编辑：对不起，我似乎误解了你所说的季度的意思。但是，据我所知，这是四舍五入到各种小数位和度数的最简单方法。
