Exponent Operator

Overview

Exponent operator is **.

var a = 0x05;
var b = a ** 2;   // 5 * 5 => 25

The differences between Math.pow and ** operation are the type of result. When it is Math.pow, the type of result is always double. However when it is ** operation, the type of result depends on the source value’s type. For example, the result will be integer when doing integer ** integer.

Operator ** is evaluated from right to left. For example see below.

a = 2 ** 3 ** 4;    // means 2 ** (3 ** 4), not (2 ** 3) ** 4.
                    //  should be 2417851639229258349412352.

Examples

Example 1. Normal Use for Integer

Code

var a = 5;
System.println(2 ** a);
System.println(a ** a);
System.println((2 ** a).isInteger ? "Integer" : "NOT Integer");
System.println((2 ** a).isBigInteger ? "BigInteger" : "NOT BigInteger");

Result

32
3125
Integer
NOT BigInteger

Example 2. Normal Use for Double

Code

var a = 5.0;
System.println(2 ** a);
System.println(a ** a);
System.println((2 ** a).isInteger ? "Integer" : "NOT Integer");
System.println((a ** 2).isInteger ? "Integer" : "NOT Integer");

Result

32
3125
NOT Integer
NOT Integer

Example 3. Normal Use for Big Integer

Code

var a = 2 ** 84;
System.println(a);
System.println(a.toString(16));
System.println(a.isInteger ? "Integer" : "NOT Integer");
System.println(a.isBigInteger ? "BigInteger" : "NOT BigInteger");

Result

19342813113834066795298816
1000000000000000000000
Integer
BigInteger

Example 4. Operator Priority

Operator ** is evaluated from right to left.

Code

var a = 2 ** 3 ** 4;
System.println(a);

Result

2417851639229258349412352