eslint/docs/rules/prefer-exponentiation-operator.md

   1 # Disallow the use of `Math.pow` in favor of the `**` operator (prefer-exponentiation-operator)
   2
   3 Introduced in ES2016, the infix exponentiation operator `**` is an alternative for the standard `Math.pow` function.
   4
   5 Infix notation is considered to be more readable and thus more preferable than the function notation.
   6
   7 ## Rule Details
   8
   9 This rule disallows calls to `Math.pow` and suggests using the `**` operator instead.
  10
  11 Examples of **incorrect** code for this rule:
  12
  13 ```js
  14 /*eslint prefer-exponentiation-operator: "error"*/
  15
  16 const foo = Math.pow(2, 8);
  17
  18 const bar = Math.pow(a, b);
  19
  20 let baz = Math.pow(a + b, c + d);
  21
  22 let quux = Math.pow(-1, n);
  23 ```
  24
  25 Examples of **correct** code for this rule:
  26
  27 ```js
  28 /*eslint prefer-exponentiation-operator: "error"*/
  29
  30 const foo = 2 ** 8;
  31
  32 const bar = a ** b;
  33
  34 let baz = (a + b) ** (c + d);
  35
  36 let quux = (-1) ** n;
  37 ```
  38
  39 ## When Not To Use It
  40
  41 This rule should not be used unless ES2016 is supported in your codebase.
  42
  43 ## Further Reading
  44
  45 * [MDN Arithmetic Operators - Exponentiation](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators#Exponentiation)
  46 * [Issue 5848: Exponentiation operator ** has different results for numbers and variables from 50 upwards](https://bugs.chromium.org/p/v8/issues/detail?id=5848)