PHP's empty in JavaScript

How to use

You you can install via yarn add locutus and require this function via const empty = require('locutus/php/var/empty').

It is important to use a bundler that supports tree-shaking so that you only ship the functions that you actually use to your browser, instead of all of Locutus, which is massive. Examples are: Parcel, webpack, or rollup.js. For server-side use this is typically less of a concern.

Examples

Please note that these examples are distilled from test cases that automatically verify our functions still work correctly. This could explain some quirky ones.

#	code	expected result
1	`empty(null)`	`true`
2	`empty(undefined)`	`true`
3	`empty([])`	`true`
4	`empty({})`	`true`
5	`empty({'aFunc' : function () { alert('humpty'); } })`	`false`

Here’s what our current JavaScript equivalent to PHP's empty looks like.

module.exports = function empty(mixedVar) {
  //  discuss at: https://locutus.io/php/empty/
  // original by: Philippe Baumann
  //    input by: Onno Marsman (https://twitter.com/onnomarsman)
  //    input by: LH
  //    input by: Stoyan Kyosev (https://www.svest.org/)
  // bugfixed by: Kevin van Zonneveld (https://kvz.io)
  // improved by: Onno Marsman (https://twitter.com/onnomarsman)
  // improved by: Francesco
  // improved by: Marc Jansen
  // improved by: Rafał Kukawski (https://blog.kukawski.pl)
  //   example 1: empty(null)
  //   returns 1: true
  //   example 2: empty(undefined)
  //   returns 2: true
  //   example 3: empty([])
  //   returns 3: true
  //   example 4: empty({})
  //   returns 4: true
  //   example 5: empty({'aFunc' : function () { alert('humpty'); } })
  //   returns 5: false

  let undef
  let key
  let i
  let len
  const emptyValues = [undef, null, false, 0, '', '0']

  for (i = 0, len = emptyValues.length; i < len; i++) {
    if (mixedVar === emptyValues[i]) {
      return true
    }
  }

  if (typeof mixedVar === 'object') {
    for (key in mixedVar) {
      if (mixedVar.hasOwnProperty(key)) {
        return false
      }
    }
    return true
  }

  return false
}

A community effort

Not unlike Wikipedia, Locutus is an ongoing community effort. Our philosophy follows The McDonald’s Theory. This means that we assimilate first iterations with imperfections, hoping for others to take issue with-and improve them. This unorthodox approach has worked very well to foster fun and fruitful collaboration, but please be reminded to use our creations at your own risk. THE SOFTWARE IS PROVIDED "AS IS" has never been more true than for Locutus.

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