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Diffstat (limited to 'doc/development/fe_guide/style/javascript.md')
| -rw-r--r-- | doc/development/fe_guide/style/javascript.md | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/doc/development/fe_guide/style/javascript.md b/doc/development/fe_guide/style/javascript.md index 334372af1f4..a2035eb1b55 100644 --- a/doc/development/fe_guide/style/javascript.md +++ b/doc/development/fe_guide/style/javascript.md @@ -98,16 +98,27 @@ class a { } ``` -## Use ParseInt +## Converting Strings to Integers -Use `ParseInt` when converting a numeric string into a number. +When converting strings to integers, `parseInt` has a slight performance advantage over `Number`, but `Number` is semantic and can be more readable. Prefer `parseInt`, but do not discourage `Number` if it significantly helps readability. + +**WARNING:** `parseInt` **must** include the [radix argument](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/parseInt). ```javascript // bad -Number('10') +parseInt('10'); + +// bad +things.map(parseInt) + +// ok +Number("106") + +// good +things.map(Number) // good -parseInt('10', 10); +parseInt("106", 10) ``` ## CSS Selectors - Use `js-` prefix @@ -297,7 +308,7 @@ Strive to write many small pure functions and minimize where mutations occur ## Export constants as primitives -Prefer exporting constant primitives with a common namespace over exporting objects. This allows for better compile-time reference checks and helps to avoid accidential `undefined`s at runtime. In addition, it helps in reducing bundle sizes. +Prefer exporting constant primitives with a common namespace over exporting objects. This allows for better compile-time reference checks and helps to avoid accidental `undefined`s at runtime. In addition, it helps in reducing bundle sizes. Only export the constants as a collection (array, or object) when there is a need to iterate over them, for instance, for a prop validator. |