Java中的pow（x，y）

Question

What's the difference between:

Math.pow ( x,y ); // x^y

To:

x^y; // x^y

?

Will I prefer to use x^y with double type numbers? Or shell I have to use always with Math.pow() method?

Answer 1

^ is the bitwise exclusive OR (XOR) operator in Java (and many other languages). It is not used for exponentiation. For that, you must use Math.pow .

Answer 2

Additionally for what was said, if you want integer powers of two, then 1 << x (or 1L << x ) is a faster way to calculate 2 ^x than Math.pow(2,x) or a multiplication loop, and is guaranteed to give you an int (or long ) result.

It only uses the lowest 5 (or 6) bits of x (ie x & 31 (or x & 63 )), though, shifting between 0 and 31 (or 63) bits.

Answer 3

在Java x ^ y是一个XOR操作。

Answer 4

x^y is not " x to the power of y ". It's " x XOR y " .