eslint/docs/src/rules/no-floating-decimal.md

   1 ---
   2 title: no-floating-decimal
   3 layout: doc
   4 rule_type: suggestion
   5 ---
   6
   7
   8
   9 Float values in JavaScript contain a decimal point, and there is no requirement that the decimal point be preceded or followed by a number. For example, the following are all valid JavaScript numbers:
  10
  11 ```js
  12 var num = .5;
  13 var num = 2.;
  14 var num = -.7;
  15 ```
  16
  17 Although not a syntax error, this format for numbers can make it difficult to distinguish between true decimal numbers and the dot operator. For this reason, some recommend that you should always include a number before and after a decimal point to make it clear the intent is to create a decimal number.
  18
  19 ## Rule Details
  20
  21 This rule is aimed at eliminating floating decimal points and will warn whenever a numeric value has a decimal point but is missing a number either before or after it.
  22
  23 Examples of **incorrect** code for this rule:
  24
  25 ::: incorrect
  26
  27 ```js
  28 /*eslint no-floating-decimal: "error"*/
  29
  30 var num = .5;
  31 var num = 2.;
  32 var num = -.7;
  33 ```
  34
  35 :::
  36
  37 Examples of **correct** code for this rule:
  38
  39 ::: correct
  40
  41 ```js
  42 /*eslint no-floating-decimal: "error"*/
  43
  44 var num = 0.5;
  45 var num = 2.0;
  46 var num = -0.7;
  47 ```
  48
  49 :::
  50
  51 ## When Not To Use It
  52
  53 If you aren't concerned about misinterpreting floating decimal point values, then you can safely turn this rule off.
  54
  55 ## Compatibility
  56
  57 * **JSHint**: W008, W047