What is false

What and who is false?
Get a list of most significant JavaScript primitives, values and objects compared with false.

Table of Contents

• Usage
• Summary table
• Example
• API
  • Constansts
  • Static Methods
  • Instance Methods

Usage

Node.js

var WhatIsFalse = require('what-is-false');

Summary table

| | ==false | ==true | if(item) --- | --- | --- | --- undefined | false | false | false null | false | false | false NaN | false | false | false true | false | true | true false | true | false | false [] | true | false | true [ 0 ] | true | false | true [ 0.1 ] | false | false | true [ {} ] | false | false | true [ 0 , 0 ] | false | false | true [ '0' ] | true | false | true [ '0' , '0' ] | false | false | true 0 | true | false | false -0 | true | false | false +0 | true | false | false 1 | false | true | true -1 | false | false | true 0.1 | false | false | true -0.1 | false | false | true '' | true | false | false '0' | true | false | true '00' | true | false | true '-0' | true | false | true '+0' | true | false | true '0.1' | false | false | true '1' | false | true | true 'true' | false | false | true 'false' | false | false | true

Example

Basic usage.

var wif = new WhatIsFalse();

console.log(wif.toString());

----------------------
Comparison with: false
----------------------
_Undefined
    undefined == false --> false
_Null
    null == false --> false
_NaN
    NaN == false --> false
_True
    true == false --> false
_False
    false == false --> true
_Empty array
    [] == false --> true
_Array with 0
    [ 0 ] == false --> true
_Array with 0.1
    [ 0.1 ] == false --> false
_Array with empty object
    [ {} ] == false --> false
_Array with 0 and 0
    [ 0 , 0 ] == false --> false
_Array with string 0
    [ '0' ] == false --> true
_Array with two string 0 elements
    [ '0' , '0' ] == false --> false
_Number 0
    0 == false --> true
_Number -0
    -0 == false --> true
_Number +0
    +0 == false --> true
_Number 1
    1 == false --> false
_Number -1
    -1 == false --> false
_Number 0.1
    0.1 == false --> false
_Number -0.1
    -0.1 == false --> false
_Empty String
    '' == false --> true
_String with 0
    '0' == false --> true
_String with double 0
    '00' == false --> true
_String with -0
    '-0' == false --> true
_String with +0
    '+0' == false --> true
_String with 0.1
    '0.1' == false --> false
_String with 1
    '1' == false --> false
_String with true
    'true' == false --> false
_String with false
    'false' == false --> false

Passing option parameter to constructor.

const option = {
    operand : false,
    result : WhatIsFalse.ALL,
    output : WhatIsFalse.JSON
};

var wif = new WhatIsFalse(option);

console.log(wif.toString());

{
 "NULL": {
  "name": "Null",
  "itemAsString": "null",
  "item": null,
  "comparison": "== false",
  "result": false,
  "IFresult": false
 },
 "UNDEFINED": {
  "name": "Undefined",
  "itemAsString": "undefined",
  "comparison": "== false",
  "result": false,
  "IFresult": false
 },
 "NAN": {
  "name": "NaN",
  "itemAsString": "NaN",
  "item": null,
  "comparison": "== false",
  "result": false,
  "IFresult": false
 },
 "TRUE": {
  "name": "True",
  "itemAsString": "true",
  "item": true,
  "comparison": "== false",
  "result": false,
  "IFresult": true
 },
 "FALSE": {
  "name": "False",
  "itemAsString": "false",
  "item": false,
  "comparison": "== false",
  "result": true,
  "IFresult": false
 },
 "ARRAYS": [
  {
   "name": "Empty array",
   "itemAsString": "[]",
   "item": [],
   "comparison": "== false",
   "result": true,
   "IFresult": true
  },
  {
   "name": "Array with 0",
   "itemAsString": "[ 0 ]",
   "item": [
    0
   ],
   "comparison": "== false",
   "result": true,
   "IFresult": true
  },
  {
   "name": "Array with 0.1",
   "itemAsString": "[ 0.1 ]",
   "item": [
    0.1
   ],
   "comparison": "== false",
   "result": false,
   "IFresult": true
  },
  {
   "name": "Array with empty object",
   "itemAsString": "[ {} ]",
   "item": [
    {}
   ],
   "comparison": "== false",
   "result": false,
   "IFresult": true
  },
  {
   "name": "Array with 0 and 0",
   "itemAsString": "[ 0 , 0 ]",
   "item": [
    0,
    0
   ],
   "comparison": "== false",
   "result": false,
   "IFresult": true
  },
  {
   "name": "Array with string 0",
   "itemAsString": "[ '0' ]",
   "item": [
    "0"
   ],
   "comparison": "== false",
   "result": true,
   "IFresult": true
  },
  {
   "name": "Array with string 0 and string 0",
   "itemAsString": "[ '0' , '0' ]",
   "item": [
    "0",
    "0"
   ],
   "comparison": "== false",
   "result": false,
   "IFresult": true
  }
 ],
 "NUMBERS": [
  {
   "name": "Number 0",
   "itemAsString": "0",
   "item": 0,
   "comparison": "== false",
   "result": true,
   "IFresult": false
  },
  {
   "name": "Number -0",
   "itemAsString": "-0",
   "item": 0,
   "comparison": "== false",
   "result": true,
   "IFresult": false
  },
  {
   "name": "Number +0",
   "itemAsString": "+0",
   "item": 0,
   "comparison": "== false",
   "result": true,
   "IFresult": false
  },
  {
   "name": "Number 1",
   "itemAsString": "1",
   "item": 1,
   "comparison": "== false",
   "result": false,
   "IFresult": true
  },
  {
   "name": "Number -1",
   "itemAsString": "-1",
   "item": -1,
   "comparison": "== false",
   "result": false,
   "IFresult": true
  },
  {
   "name": "Number 0.1",
   "itemAsString": "0.1",
   "item": 0.1,
   "comparison": "== false",
   "result": false,
   "IFresult": true
  },
  {
   "name": "Number -0.1",
   "itemAsString": "-0.1",
   "item": -0.1,
   "comparison": "== false",
   "result": false,
   "IFresult": true
  }
 ],
 "STRINGS": [
  {
   "name": "Empty String",
   "itemAsString": "''",
   "item": "",
   "comparison": "== false",
   "result": true,
   "IFresult": false
  },
  {
   "name": "String with 0",
   "itemAsString": "'0'",
   "item": "0",
   "comparison": "== false",
   "result": true,
   "IFresult": true
  },
  {
   "name": "String with double 0",
   "itemAsString": "'00'",
   "item": "00",
   "comparison": "== false",
   "result": true,
   "IFresult": true
  },
  {
   "name": "String with -0",
   "itemAsString": "'-0'",
   "item": "-0",
   "comparison": "== false",
   "result": true,
   "IFresult": true
  },
  {
   "name": "String with +0",
   "itemAsString": "'+0'",
   "item": "+0",
   "comparison": "== false",
   "result": true,
   "IFresult": true
  },
  {
   "name": "String with 0.1",
   "itemAsString": "'0.1'",
   "item": "0.1",
   "comparison": "== false",
   "result": false,
   "IFresult": true
  },
  {
   "name": "String with 1",
   "itemAsString": "'1'",
   "item": "1",
   "comparison": "== false",
   "result": false,
   "IFresult": true
  },
  {
   "name": "String with true",
   "itemAsString": "'true'",
   "item": "true",
   "comparison": "== false",
   "result": false,
   "IFresult": true
  },
  {
   "name": "String with false",
   "itemAsString": "'false'",
   "item": "false",
   "comparison": "== false",
   "result": false,
   "IFresult": true
  }
 ]
}

API

Constants

• WhatIsFalse.ALL = 'all'
• WhatIsFalse.TRUE = 'true'
• WhatIsFalse.FALSE = 'false'
• WhatIsFalse.JSON = 'json'

Static Methods

WhatIsFalse

See: WhatIsFalse.factory for details on instantiation.

WhatIsFalse.factory([options])

WhatIsFalse instance creator

• options - options (optional)
  • operand - boolean used for comparison (default false)
  • result - string WhatIsFalse.FALSE or WhatIsFalse.TRUE or WhatIsFalse.ALL (default): only true, false or all comparison results with operand will be displayed, respectively.
  • output - string WhatIsFalse.JSON or empty (defalut)

Instance Methods

instance.toString()

See: instance.compare for details.

instance.compare()

Make the comparison and return the result as string.

instance.eq2(item)

Compare item to false (or true if operand option is true) and return the comparison result.