Check whether a value exists in JSON object

Question

I have the next JSON    var JSONObject     animals     name  cat     name  dog        What is the best way to know if the  dog  value exists in the JSON object   Thanks   Solution 1  var JSONObject     animals     name  cat     name  dog          for  i 0  i  lt  JSONObject animals length  i          if  JSONObject animals i  name     dog           return true    return false    Solution 2  JQuery   var JSONObject     animals     name  cat     name  dog            map JSONObject animals  function elem  index     if  elem name     dog         return true      return false    Solution 3  using some   method   function  isContains json  value        let contains   false      Object keys json  some key   gt            contains   typeof json key       object              isContains json key   value    json key      value          return contains              return contains

User · Answer

This example puts your JSON into proper format and does an existence check. I use jquery for convenience.

http://jsfiddle.net/nXFxC/

<!-- HTML -->
<span id="test">Hello</span><br>
<span id="test2">Hello</span>

//Javascript

$(document).ready(function(){
    var JSON = {"animals":[{"name":"cat"}, {"name":"dog"}]};

if(JSON.animals[1].name){      
$("#test").html("It exists");
}
if(!JSON.animals[2]){       
$("#test2").html("It doesn't exist");
}
});

User · Answer

Why not JSON stringify and  includes    You can easily check if a JSON object includes a value by turning it into a string and checking the string  console log JSON stringify JSONObject  includes  quot dog quot    -- gt  true  Edit  make sure to check browser compatibility for  includes

User · Answer

Check for a value single level  const hasValue   Object values json  includes  bar      Check for a value multi-level  function hasValueDeep json  findValue        const values   Object values json       let hasValue   values includes findValue       values forEach function value            if  typeof value      object                 hasValue   hasValue    hasValueDeep value  findValue                        return hasValue

User · Answer

var JSONObject     quot animals quot     name  quot cat quot     name  quot dog quot        var Duplicate  JSONObject  find s   gt  s name    quot cat quot            if  typeof  Duplicate       quot undefined quot                alert  quot Not Exist quot               return            else               if  JSON stringify Duplicate  length  gt  0                    alert  quot Value Exist quot                    return

User · Answer

iterate through the array and check its name value

User · Answer

I think this is the best and easy way    lista         lista        name    Diego       ConvertFrom-Json   lista        name    Monica       ConvertFrom-Json   lista        name    Celia       ConvertFrom-Json   lista        name    Quin       ConvertFrom-Json   if   Diego  -in  lista name        Write-Host  is in the list      return  true    else       Write-Host  not in the list      return  false

User · Answer

You could improve on the answer from Ponmudi VN    Shorter Code Look for a key and a value   See this fiddle  https   jsfiddle net solarbaypilot sn3wtea2   function  isContains json  keyname  value     return Object keys json  some key   gt            return typeof json key       object              isContains json key   keyname  value    key     keyname  amp  amp  json key      value             var JSONObject     animals     name  cat     name  dog        document getElementById  dog   innerHTML    isContains JSONObject   name    dog    document getElementById  puppy   innerHTML    isContains JSONObject   name    puppy

User · Answer

Below function can be used to check for a value in any level in a JSON  function  isContains json  value        let contains   false      Object keys json  some key   gt            contains   typeof json key       object     isContains json key   value    json key      value           return contains              return contains       then to check if JSON contains the value   isContains JSONObject   dog     See this fiddle  https   jsfiddle net ponmudi uykaacLw   Most of the answers mentioned here compares by  name  key   But no need to care about the key  can just checks if JSON contains the given value  So that the function can be used to find any value irrespective of the key

User · Answer

var JSON      name   cat      name   dog       The JSON variable refers to an array of object with one property called  name   I don t know of the best way but this is what I do   var hasMatch  false   for  var index   0  index  lt  JSON length    index      var animal   JSON index     if animal Name     dog       hasMatch   true     break

[javascript] Check whether a value exists in JSON object

Examples related to javascript

Examples related to json