# Quirky behaviour of "\" **URL:** \ **Category:** I have questions\ **Created:** [September 6, 2021, 8:01am UTC](https://es.discourse.group/t/quirky-behaviour-of-space/972 "2021-09-06T08:01:31Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![jithujoshyjy](https://yyz2.discourse-cdn.com/free1/user_avatar/es.discourse.group/jithujoshyjy/32/399_2.png) [@jithujoshyjy](https://es.discourse.group/u/jithujoshyjy)\ **Post date:** [September 6, 2021, 8:01am UTC](https://es.discourse.group/t/quirky-behaviour-of-space/972/1 "2021-09-06T08:01:31Z")
I have lately been bugged with an issue of how js consider certain strings being true / false in a boolean context; ```javascript let x = Boolean(" ") // Boolean("") console.log(x) // true let y = " " == false // "" == false console.log(y) // true ``` Why is `""` considered **true** when passed to the Boolean constructor and at the same time considered equivalent to **false** using the `==` operator? ---
**Author:** ![lightmare](https://yyz2.discourse-cdn.com/free1/user_avatar/es.discourse.group/lightmare/32/843_2.png) [@lightmare](https://es.discourse.group/u/lightmare)\ **Post date:** [September 6, 2021, 9:17am UTC](https://es.discourse.group/t/quirky-behaviour-of-space/972/2 "2021-09-06T09:17:01Z")
Because [loose comparison](https://tc39.es/ecma262/multipage/abstract-operations.html#sec-islooselyequal) is utterly ridiculous :D In particular, you're hitting step 10. > If [Type](https://tc39.es/ecma262/multipage/ecmascript-data-types-and-values.html#sec-ecmascript-data-types-and-values)(y) is Boolean, return [IsLooselyEqual](https://tc39.es/ecma262/multipage/abstract-operations.html#sec-islooselyequal)(x, ! [ToNumber](https://tc39.es/ecma262/multipage/abstract-operations.html#sec-tonumber)(y)). ```javascript > '-0E+123' == false true > '123E-400' == false true ``` ---
**Author:** ![jithujoshyjy](https://yyz2.discourse-cdn.com/free1/user_avatar/es.discourse.group/jithujoshyjy/32/399_2.png) [@jithujoshyjy](https://es.discourse.group/u/jithujoshyjy)\ **Post date:** [September 6, 2021, 10:04am UTC](https://es.discourse.group/t/quirky-behaviour-of-space/972/3 "2021-09-06T10:04:51Z")
why does this behaviour occur only for `""` and not for "%", "\_", or any other strings?? why does loose equality treat it as an empty string? ---
**Author:** ![lightmare](https://yyz2.discourse-cdn.com/free1/user_avatar/es.discourse.group/lightmare/32/843_2.png) [@lightmare](https://es.discourse.group/u/lightmare)\ **Post date:** [September 6, 2021, 10:32am UTC](https://es.discourse.group/t/quirky-behaviour-of-space/972/4 "2021-09-06T10:32:03Z")
If you follow the algorithm, both sides of ` == ` get eventually coerced to Number. > 1. If [Type](https://tc39.es/ecma262/multipage/ecmascript-data-types-and-values.html#sec-ecmascript-data-types-and-values)(y) is Boolean, return [IsLooselyEqual](https://tc39.es/ecma262/multipage/abstract-operations.html#sec-islooselyequal)(x, ! [ToNumber](https://tc39.es/ecma262/multipage/abstract-operations.html#sec-tonumber)(y)). > 2. If [Type](https://tc39.es/ecma262/multipage/ecmascript-data-types-and-values.html#sec-ecmascript-data-types-and-values)(x) is String and [Type](https://tc39.es/ecma262/multipage/ecmascript-data-types-and-values.html#sec-ecmascript-data-types-and-values)(y) is Number, return [IsLooselyEqual](https://tc39.es/ecma262/multipage/abstract-operations.html#sec-islooselyequal)(! [ToNumber](https://tc39.es/ecma262/multipage/abstract-operations.html#sec-tonumber)(x), y). So: ```javascript "string" == false // becomes "string" == Number(false) // becomes Number("string") == Number(false) ``` ```javascript " " == false // because Number(false) === 0 Number(" ") === 0 ``` ```javascript "%" != false // because Number("%") == NaN NaN !== 0 ``` ---
**Author:** ![jithujoshyjy](https://yyz2.discourse-cdn.com/free1/user_avatar/es.discourse.group/jithujoshyjy/32/399_2.png) [@jithujoshyjy](https://es.discourse.group/u/jithujoshyjy)\ **Post date:** [September 6, 2021, 12:18pm UTC](https://es.discourse.group/t/quirky-behaviour-of-space/972/5 "2021-09-06T12:18:16Z")
Number(" ") === 0 but how is this coercion done?? Based on unicode code point of ``?? but that is U+0020. Null has the corresponding U+0000 code point. Number(" ") === 0; how is this coercion even reasonable?? I mean if: ```javascript Number("") === NaN // and should also be Number("") === NaN // it's illogical and inconsistent for it to be 0 Number("") === 0 // here it makes some sense for an empty // string to be coerced to 0 ``` ---
**Author:** ![lightmare](https://yyz2.discourse-cdn.com/free1/user_avatar/es.discourse.group/lightmare/32/843_2.png) [@lightmare](https://es.discourse.group/u/lightmare)\ **Post date:** [September 6, 2021, 12:43pm UTC](https://es.discourse.group/t/quirky-behaviour-of-space/972/6 "2021-09-06T12:43:26Z")
> [@jithujoshyjy](#): > > Number(" ") === 0; how is this coercion even reasonable?? It is not. But that's how it was "standardized". > [@jithujoshyjy](#): > > ```javascript > Number("") === 0 > // here it makes some sense for an empty > // string to be coerced to 0 > > ``` To me that doesn't make sense, either. There is no number in an empty string, it should've returned NaN. ---
**Author:** ![lightmare](https://yyz2.discourse-cdn.com/free1/user_avatar/es.discourse.group/lightmare/32/843_2.png) [@lightmare](https://es.discourse.group/u/lightmare)\ **Post date:** [September 6, 2021, 1:07pm UTC](https://es.discourse.group/t/quirky-behaviour-of-space/972/7 "2021-09-06T13:07:15Z")
Missed this question: > [@jithujoshyjy](#): > > Number(" ") === 0 > but how is this coercion done?? > Based on unicode code point of ``?? No. `Number("string")` tries to parse it, stripping leading/trailing whitespace. A string of whitespace is treated like an empty string. ---
**Author:** ![jithujoshyjy](https://yyz2.discourse-cdn.com/free1/user_avatar/es.discourse.group/jithujoshyjy/32/399_2.png) [@jithujoshyjy](https://es.discourse.group/u/jithujoshyjy)\ **Post date:** [September 6, 2021, 2:23pm UTC](https://es.discourse.group/t/quirky-behaviour-of-space/972/8 "2021-09-06T14:23:27Z")
barbaric logic of standardisation; sad but we can't do much about it😠 Anyway thanks @lightmare for helping me out here! ---
**Author:** ![jithujoshyjy](https://yyz2.discourse-cdn.com/free1/user_avatar/es.discourse.group/jithujoshyjy/32/399_2.png) [@jithujoshyjy](https://es.discourse.group/u/jithujoshyjy)\ **Post date:** [September 6, 2021, 2:30pm UTC](https://es.discourse.group/t/quirky-behaviour-of-space/972/9 "2021-09-06T14:30:04Z")
So to wrap up here's what I understood: ```javascript // the normalisation process: // step.1 " " == false // step.2 stripSpaces(" ") == false // step.3 Number("") == Number(false) // step.4 0 == 0 // step.5 true ```