JavaScript loop through json array

Question

I am trying to loop through the following json array        id    1      msg    hi      tid    2013-05-05 23 35      fromWho    hello1 email se          id    2      msg    there      tid    2013-05-05 23 45      fromWho    hello2 email se      And have tried the following  for  var key in data       if  data hasOwnProperty key           console log data key  id            But for some reason i am only getting the first part  id 1 values   Any ideas

User · Answer

Well  all I can see there is that you have two JSON objects  seperated by a comma  If both of them were inside an array         it would make more sense   And  if they ARE inside of an array  then you would just be using the standard  for var i   0     type of loop  As it is  I think it s going to try to retrieve the  id  property of the string  1   then  id  of  hi   and so on

User · Answer

It must be an array if you want to iterate over it  You re very likely missing   and     var x           id    1            msg    hi            tid    2013-05-05 23 35            fromWho    hello1 email se            id    2            msg    there            tid    2013-05-05 23 45            fromWho    hello2 email se       var  output       output    for var i   0  i  lt  x length  i          console log x i  id       Check out this jsfiddle  http   jsfiddle net lpiepiora kN7yZ

User · Answer

var arr            id    1      msg    hi      tid    2013-05-05 23 35      fromWho    hello1 email se            id    2      msg    there      tid    2013-05-05 23 45      fromWho    hello2 email se           forEach method for easy implementation   arr forEach function item     console log  ID      item id     console log  MSG      item msg     console log  TID      item tid     console log  FROMWHO      item fromWho

User · Answer

There s a few problems in your code  first your json must look like    var json       id     1     msg       hi    tid     2013-05-05 23 35    fromWho    hello1 email se        id     2     msg       there    tid     2013-05-05 23 45    fromWho    hello2 email se        Next  you can iterate like this    for  var key in json    if  json hasOwnProperty key       alert json key  id     alert json key  msg         And it gives perfect result   See the fiddle here   http   jsfiddle net zrSmp

User · Answer

It is working  I just added square brackets to JSON data  The data is   var data                     id    1            msg    hi             tid    2013-05-05 23 35             fromWho    hello1 email se                           id    2             msg    there             tid    2013-05-05 23 45             fromWho    hello2 email se            And the loop is   for  var key in data       if  data hasOwnProperty key              alert data key  id

User · Answer

Since i already started looking into it   var data           id    1        msg    hi        tid    2013-05-05 23 35        fromWho    hello1 email se            id    2        msg    there        tid    2013-05-05 23 45        fromWho    hello2 email se       And this function   var iterateData  function data     for  var key in data           if  data hasOwnProperty key               console log data key  id                      You can call it like this  iterateData data      write 1 and 2 to the console   Update after Erics comment  As eric pointed out a for in loop for an array can have unexpected results  The referenced question has a lengthy discussion about pros and cons    Test with for var i      But it seems that the follwing is quite save   for var i   0  i  lt  array length  i    1    Although a test in chrome had the following result  var ar       ar 0     a    ar 1     b   ar 4     c    function forInArray ar         for var i   0  i  lt  ar length  i    1           console log ar i          calling the function    returns a b  undefined  undefined  c  undefined forInArray ar      Test with  forEach    At least in chrome 30 this works as expected  var logAr   function element  index  array        console log  a     index            element     ar forEach logAr      returns a 0    a  a 1    b  a 4    c   Links   see for in at the mdn the new forEach method a comment that states that array comprehension makes for in less bad Array comprehension introduced with javascript 1 7 in firefox 2  yes 2

User · Answer

try this   var json           id     1         msg       hi        tid     2013-05-05 23 35        fromWho    hello1 email se            id     2         msg       there        tid     2013-05-05 23 45        fromWho    hello2 email se       json forEach  item    gt      console log  ID      item id     console log  MSG      item msg     console log  TID      item tid     console log  FROMWHO      item fromWho

User · Answer

A short solution using map and an arrow function   x000D   x000D  var data      x000D     id    1   x000D     msg    hi   x000D     tid    2013-05-05 23 35   x000D     fromWho    hello1 email se  x000D       x000D     id    2   x000D     msg    there   x000D     tid    2013-05-05 23 45   x000D     fromWho    hello2 email se  x000D      x000D  data map  item  i    gt  console log  Index    i   Id    item id    x000D   x000D   x000D    And to cover the cases when the property  id  is not present use filter    x000D   x000D  var data      x000D     id    1   x000D     msg    hi   x000D     tid    2013-05-05 23 35   x000D     fromWho    hello1 email se  x000D       x000D     id    2   x000D     msg    there   x000D     tid    2013-05-05 23 45   x000D     fromWho    hello2 email se  x000D       x000D     msg    abcde   x000D     tid    2013-06-06 23 46   x000D     fromWho    hello3 email se  x000D      x000D   x000D  data filter item  gt item hasOwnProperty  id    x000D                   map  item  i    gt  console log  Index    i   Id    item id    x000D   x000D   x000D

User · Answer

your data snippet need to be expanded a little  and it has to be this way to be proper json  notice I just include the array name attribute  quot item quot    quot item quot         quot id quot    quot 1 quot      quot msg quot    quot hi quot      quot tid quot    quot 2013-05-05 23 35 quot      quot fromWho quot    quot hello1 email se quot          quot id quot    quot 2 quot      quot msg quot    quot there quot      quot tid quot    quot 2013-05-05 23 45 quot      quot fromWho quot    quot hello2 email se quot       your java script is simply var objCount   json item length  for   var x 0  x  lt  objCount   xx           var curitem   json item x

User · Answer

Your JSON should look like this   var json           id     1         msg       hi        tid     2013-05-05 23 35        fromWho    hello1 email se            id     2         msg       there        tid     2013-05-05 23 45        fromWho    hello2 email se        You can loop over the Array   like this   for var i   0  i  lt  json length  i          var obj   json i        console log obj id       Or like this  suggested from Eric  be careful with IE support  json forEach function obj    console log obj id

User · Answer

A bit late but i hope i may help others  D  your json needs to look like something Niklas already said  And then here you go   for var key in currentObject           if currentObject hasOwnProperty key               console info key          currentObject key                     if you have an Multidimensional array  this is your code    for  var i   0  i  lt  multiDimensionalArray length  i          var currentObject   multiDimensionalArray i      for var key in currentObject               if currentObject hasOwnProperty key                   console info key          currentObject key

[javascript] JavaScript loop through json array?

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