When you need to check a value for presence, don't rely on JavaScript since it considers 0 or "0" false. Also don't rely on LoDash's _.isEmpty:
if ('0') { ... } // false
if (0) { ... } // false
^
if (!.isEmpty('0')) { ... } // true (= good)
if (!.isEmpty(0)) { ... } // false (= not good)
This is because
isEmpty it is only meant for objects with a length
Show archive.org snapshot
.
While the name implies that it's meant only for collections, you probably still want something like isBlank or isPresent that return true/false for objects humans would normally consider blank or present.
Here is some CoffeeScript that provides _.isBlank and _.isPresent via LoDash/Underscore.js mixins:
_.mixin
isBlank: (object) ->
switch typeof object
when 'boolean' then false
when 'function' then false
when 'number' then isNaN(object)
else _.isEmpty(object)
isPresent: (object) ->
!_.isBlank(object)
,
chain: false
Use them like this:
_.isBlank(0) // false
_.isBlank(23) // false
_.isBlank('') // true
^
_.isPresent(null) // false
_.isPresent(NaN) // false
The chain: false option above also allows to use them as terminal methods:
_(23).isBlank() // false
_(23).isPresent() // true
