Disallow Floating Decimals (no-floating-decimal)

The --fix option on the command line can automatically fix some of the problems reported by this rule.

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:

var num = .5;
var num = 2.;
var num = -.7;

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.

Rule Details

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.

Examples of incorrect code for this rule:

/*eslint no-floating-decimal: "error"*/

var num = .5;
var num = 2.;
var num = -.7;

Examples of correct code for this rule:

/*eslint no-floating-decimal: "error"*/

var num = 0.5;
var num = 2.0;
var num = -0.7;

When Not To Use It

If you aren’t concerned about misinterpreting floating decimal point values, then you can safely turn this rule off.


  • JSHint: W008


This rule was introduced in ESLint 0.0.6.


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