[javascript] Uncaught TypeError: Cannot use 'in' operator to search for 'length' in

Uncaught TypeError: Cannot use 'in' operator to search for 'length' in "

This is the error I receive when I try to do a $.each to this JSON object :

{"type":"Anuncio","textos":["Probando esto","$ 20150515"],"submit":"codParameters?___DDSESSIONID\u003d14EA4721A904D6DD71591156996E29F7%3A%2FMobilTest"}

I have also tried to do the same with stringify, but I receive the same error:

{\"type\":\"Anuncio\",\"textos\":[\"Probando esto\",\"$ 20150515\"],\"submit\":\"codParameters?___DDSESSIONID\\u003d06CBEC9D1A53616EFF703A8C71FBC2B4%3A%2FMobilTest\"}"

If I remove parameters ___DDSESSIONID\\u003d06CBEC9D1A53616EFF703A8C71FBC2B4%3A%2FMobilTest from the object the $.each works fine.

Why might this be happening?

The in operator only works on objects. You are using it on a string. Make sure your value is an object before you using $.each. In this specific case, you have to parse the JSON:

$.each(JSON.parse(myData), ...);

maybe you forget to add parameter dataType:'json' in your $.ajax

$.ajax({
   type: "POST",
   dataType: "json",
   url: url,
   data: { get_member: id },
   success: function( response ) 
   { 
     //some action here
   },
   error: function( error )
   {
     alert( error );
   }
});

The only solution that worked for me and $.each was definitely causing the error. so i used for loop and it's not throwing error anymore.

Example code

     $.ajax({
            type: 'GET',
            url: 'https://example.com/api',
            data: { get_param: 'value' },
            success: function (data) {
                for (var i = 0; i < data.length; ++i) {
                    console.log(data[i].NameGerman);
                }
            }
        });