为什么java Math.pow参数加倍？ [英] why java Math.pow arguments double?

问题描述

为什么Java中的Math.pow API有双重参数，那么使用double的写法是什么原理呢？

为了计算浮点数，四舍五入错误等等。都涉及到为什么没有单独的API来计算整数？

为什么没有单独的方法
<解决方案

结果pow往往是非理性的，分数或太大，作为 long 存储，如果你想使用您可以使用的整数的权力

  BigInteger bi = BigInteger.valueOf（100）; 
 BigInteger bi2 = bi.pow（20）; // 10 ^ 40 
  

另一个原因可能是Math有许多从C中取的函数，来自常见的CPU指令集。 C只有一个浮点型方法，而x64只有浮点型的pow。

why Math.pow API in java is with double arguments, what is the rationale or use of writing with double ?

As caluclating the floats and double involve precision, round off errors etc.. are involved why not there is no separate API to caluclate with integers ?

Why there is no separate method

解决方案

The results of pow are often irrational, fractional or too large to store as a long, If you want to use powers of integers you can use

 BigInteger bi = BigInteger.valueOf(100);
 BigInteger bi2 = bi.pow(20); // 10^40

Another reason maybe that Math has many function which are taken from C, and also from common CPU instructions sets. C only has a floating point method and x64 only has the floating point version of pow.

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