How can I check if a JSON is empty in NodeJS

Question

I have a function that checks to see whether or not a request has any queries  and does different actions based off that  Currently  I have if query  do this else something else  However  it seems that when there is no query data  I end up with a    JSON object  As such  I need to replace if query  with if query isEmpty    or something of that sort  Can anybody explain how I could go about doing this in NodeJS  Does the V8 JSON object have any functionality of this sort

User · Answer

const isEmpty    value    gt        value     undefined        value     null         typeof value      object   amp  amp  Object keys value  length     0          typeof value      string   amp  amp  value trim   length     0       module exports   isEmpty

User · Answer

You can use either of these functions      This should work in node js and other ES5 compliant implementations  function isEmptyObject obj      return  Object keys obj  length        This should work both there and elsewhere  function isEmptyObject obj      for  var key in obj        if  Object prototype hasOwnProperty call obj  key           return false              return true      Example usage   if  isEmptyObject query          There are no queries    else        There is at least one query       or at least the query object is not empty

User · Answer

You can use this   var isEmpty   function obj      return Object keys obj  length     0      or this   function isEmpty obj      return  Object keys obj  length  gt  0      You can also use this   function isEmpty obj      for var prop in obj        if obj hasOwnProperty prop         return false         return true      If using underscore or jQuery  you can use their isEmpty or isEmptyObject calls

User · Answer

My solution   let isEmpty    val    gt        let typeOfVal   typeof val      switch typeOfVal           case  object               return  val length    0      Object keys val  length              break          case  string               let str   val trim                return str          str    undefined              break          case  number               return val                    break          default              return val          val    undefined           console log isEmpty  1 2 4 5        false console log isEmpty  id  1  name   Trung  age  29        false console log isEmpty  TrunvNV        false console log isEmpty 8       false console log isEmpty          true console log isEmpty             true console log isEmpty          true console log isEmpty          true

User · Answer

If you have compatibility with Object keys  and node does have compatibility  you should use that for sure    However  if you do not have compatibility  and for any reason using a loop function is out of the question - like me  I used the following solution    JSON stringify obj             Consider this solution a  last resort  use only if must    See in the comments  there are many ways in which this solution is not ideal     I had a last resort scenario  and it worked perfectly

User · Answer

Object keys myObj  length     0    As there is need to just check if Object is empty it will be better to directly call a native method  Object keys myObj  length which returns the array of keys by internally iterating with for  in loop As Object hasOwnProperty returns a boolean result based on the property  present in an object which itself iterates with for  in loop and will have time complexity O N2    On the other hand  calling a UDF which itself has above two implementations or other will work fine for small object but will block the code which will have severe impact on overall perormance if Object size is large unless nothing else is waiting in the event loop

[javascript] How can I check if a JSON is empty in NodeJS?

Examples related to javascript

Examples related to json

Examples related to node.js

Examples related to v8