How to print json property name?

Question

I have a json in the following format:

{
 "nm_questionario":{"isEmpty":"MSGE1 - Nome do Question&aacute;rio"},
 "ds_questionario":{"isEmpty":"MSGE1 - Descri&ccedil;&atilde;o do Question&aacute;rio"},
 "dt_inicio_vigencia":{"isEmpty":"MSGE1 - Data de Vig&ecirc;ncia"}
}

how can I print the names of the properties using javascript? I want to retrieve the names nm_questionario, dt_inicio_vigencia and ds_questionario. Tried many things already but to no avail.

You'd *loop* over the properties and *print* them...!? – deceze Jul 31 '15 at 13:21 — deceze, Jul 31 '15 at 13:21

score 5 · Answer 1 · answered Jul 31 '15 at 13:25

Object.keys()

var obj = {
 "nm_questionario":{"isEmpty":"MSGE1 - Nome do Question&aacute;rio"},
 "ds_questionario":{"isEmpty":"MSGE1 - Descri&ccedil;&atilde;o do Question&aacute;rio"},
 "dt_inicio_vigencia":{"isEmpty":"MSGE1 - Data de Vig&ecirc;ncia"}
};
console.log(Object.keys(obj));

score 3 · Accepted Answer · answered Jul 31 '15 at 13:25

3

You can get an array of the keys with var keys = Object.keys(JSON.parse(jsonString));. Just keep in mind that it only works on IE9+.

answered Jul 31 '15 at 13:25

gfpacheco

2,655
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That was it man! It works on Firefox also! Many thanks! – XVirtusX Jul 31 '15 at 13:41
Yes, sure! I mean it won't work on IE earlier than 9 – gfpacheco Jul 31 '15 at 15:09

score 1 · Answer 3 · answered Jul 31 '15 at 13:24

1

A simple loop will work. Iterate over all the indices. If you want to get the content use object[index]

var object={"nm_questionario":{"isEmpty":"MSGE1 - Nome do Question&aacute;rio"},"ds_questionario":{"isEmpty":"MSGE1 - Descri&ccedil;&atilde;o do Question&aacute;rio"},"dt_inicio_vigencia":{"isEmpty":"MSGE1 - Data de Vig&ecirc;ncia"}};
for(var index in object) { 
    console.log(index);
}

answered Jul 31 '15 at 13:24

depperm

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already tried that. But it only outputs the number of keys. (0, 1, 2...) – XVirtusX Jul 31 '15 at 13:39

score 1 · Answer 4 · answered Jul 31 '15 at 13:24

1

If you want to access the names of the properties, you can loop over them like this:

var object = //put your object here
for(var key in object) {
    if(object.hasOwnProperty(key)) {
        var property = object[key];
        //do whatever you want with the property here, for example console.log(property)
    }
}

answered Jul 31 '15 at 13:24

ralh

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Alreay tried that. But I only get one letter of the entire json in each loop. First iteration outputs "{", second iteration outputs ' " ' third outputs "n" and so on... – XVirtusX Jul 31 '15 at 13:39
Is `object` a JSON - a string representing a JS object - or a proper JS object? If it's a JSON, you need to do `JSON.parse(yourJSONHere)`. – ralh Jul 31 '15 at 13:41

How to print json property name?

4 Answers4