Java 有指数运算符吗？
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Does Java have an exponential operator?
提问by user3362992
Is there an exponential operator in Java?
Java中有指数运算符吗？
For example, if a user is prompted to enter two numbers and they enter 3and 2, the correct answer would be 9.
例如，如果提示用户输入两个数字并且他们输入3和2，则正确答案是9。
import java.util.Scanner;
public class Exponentiation {
public static double powerOf (double p) {
double pCubed;
pCubed = p*p;
return (pCubed);
}
public static void main (String [] args) {
Scanner in = new Scanner (System.in);
double num = 2.0;
double cube;
System.out.print ("Please put two numbers: ");
num = in.nextInt();
cube = powerOf(num);
System.out.println (cube);
}
}
采纳答案by Jason Pather
To do this with user input:
要使用用户输入执行此操作：
public static void getPow(){
Scanner sc = new Scanner(System.in);
System.out.println("Enter first integer: "); // 3
int first = sc.nextInt();
System.out.println("Enter second integer: "); // 2
int second = sc.nextInt();
System.out.println(first + " to the power of " + second + " is " +
(int) Math.pow(first, second)); // outputs 9
回答by Paul Draper
There is no operator, but there is a method.
没有运算符，但有一种方法。
Math.pow(2, 3) // 8.0
Math.pow(3, 2) // 9.0
FYI, a common mistake is to assume 2 ^ 3is 2 to the 3rd power. It is not. The caret is a valid operator in Java (and similar languages), but it is binary xor.
仅供参考，一个常见的错误是假设2 ^ 3是 2 的 3 次方。它不是。插入符号是 Java（和类似语言）中的有效运算符，但它是二进制异或。
回答by PlasmaPower
There is the Math.pow(double a, double b)method. Note that it returns a double, you will have to cast it to an int like (int)Math.pow(double a, double b).
有Math.pow(double a, double b)方法。请注意，它返回一个双精度值，您必须将其转换为 int 类型，例如(int)Math.pow(double a, double b).
回答by Kedarnath Calangutkar
you can use the pow method from the Math class. The following code will output 2 raised to 3 (8)
您可以使用 Math 类中的 pow 方法。以下代码将输出 2 升至 3 (8)
System.out.println(Math.pow(2, 3));
回答by libik
The easiest way is to use Math library.
最简单的方法是使用 Math 库。
Use Math.pow(a, b)and the result will be a^b
使用Math.pow(a, b)，结果将是a^b
If you want to do it yourself, you have to use for-loop
如果你想自己做，你必须使用for循环
// Works only for b >= 1
public static double myPow(double a, int b){
double res =1;
for (int i = 0; i < b; i++) {
res *= a;
}
return res;
}
Using:
使用：
double base = 2;
int exp = 3;
double whatIWantToKnow = myPow(2, 3);
回答by Rajesh D
In case if anyone wants to create there own exponential function using recursion, below is for your reference.
如果有人想使用递归创建自己的指数函数，以下供您参考。
public static double power(double value, double p) {
if (p <= 0)
return 1;
return value * power(value, p - 1);
}
