Insert a array in a JSON object

Question

I have two arrays called one and two. one contains string values and two int values. I'm trying:

var messageObject = { 'One': one,
                       'Two': two};
var serializedJSON = JSON.stringify(messageObject);
var json = JSON.parse(serializedJSON);
alert(json.One);

I'm getting "Undefined", though the array is populated. They are receiving data from a database, like this:

db.transaction(function(transaction) {
    transaction.executeSql('SELECT * FROM aluno', [], function(transaction, results) {
        len = results.rows.length, i;
        for (i = 0; i < results.rows.length; i++) {
            one[i] = results.rows.item(i).fieldOne;
            two[i] = results.rows.item(i).fieldTwo;
        }            
    }, null);
});

See the code:

http://jsfiddle.net/U4C6r/2/

are you sure you defined one and two before defining messageObject ? — Paolo
– Paolo, Commented Apr 19, 2014 at 18:29
See the update, please. Is there any problem receiving data from database? — MCGBra
– MCGBra, Commented Apr 19, 2014 at 18:45

Sebastian G. Marinescu · Accepted Answer · 2014-04-19 19:26:28Z

1

Edited Answer:

The problem seems to be with the DB-Query-Code. Either the query or the callback get never executed, see: http://jsfiddle.net/U4C6r/11/

Original Answer:

var messageObject = { 
  'One': one,
  'Two': two
};

If you define your keys as strings, you should access them as such:

console.log(json['One']);

If you'd like to have them as properties on the object, you should do:

var messageObject = { 
  One: one,
  Two: two
};

Then you could access the data in a chaining fashion, like you want to:

console.log(json.One);

You should also see the difference here and in your IDE by the specific Syntax-Highlighting - see it? :)

edited Apr 19, 2014 at 19:26

answered Apr 19, 2014 at 18:52

Sebastian G. Marinescu

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1 Comment

Sebastian G. Marinescu Over a year ago

Okay, so this wasn't the problem here - sorry. It seems your DB-Execution-Callback is never executed, see: jsfiddle.net/U4C6r/4

MCGBra · Accepted Answer · 2014-04-19 19:44:07Z

0

EDIT to updated: put breakpoint as you read the values from webSQL and check the structure of object you get within loop inspect this obj results.rows.item(i)

Also change your script to this. I am assuming you have global var one = []; and var two = []; declared.

var dynamicArrayContainer = { one : [], 
two : []};
db.transaction(function(transaction) {
transaction.executeSql('SELECT * FROM table', [], function(transaction, results) {
    for (var i = 0; i < results.rows.length; i++) {
        dynamicArrayContainer .one.push(results.rows.item(i).fieldOne);
        dynamicArrayContainer .two.push( results.rows.item(i).fieldTwo);
    }            
}, null);
});

Try this, put your values directly, as debug exercise

var serializedJSON = JSON.stringify(dynamicArrayContainer);
var json = JSON.parse(serializedJSON);
alert(json.one);

edited Apr 19, 2014 at 19:44

MCGBra

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answered Apr 19, 2014 at 18:27

Matas Vaitkevicius

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4 Comments

MCGBra Over a year ago

See the update, please. Is there any problem receiving data from database?

MCGBra Over a year ago

I try, it worked. But I need creating the array dinamically. Would you try it, please?

MCGBra Over a year ago

I didn't know exists that "push" method. Thank for that. But still doesn't work out. Can you have a look at the code? jsfiddle.net/U4C6r/10

MCGBra Over a year ago

I tried it in my real code. It worked properly. The JSFiddle my has some problem with databases, I don't know. Thanks!

erosman · Accepted Answer · 2014-04-19 18:55:38Z

0

Try this:

var messageObject = { One: 'one',
                       Two: 'two'};
var serializedJSON = JSON.stringify(messageObject);
var json = JSON.parse(serializedJSON);
alert(json.One);

Good luck :)

Update: Enquirer edited the query after this reply was posted. This reply pertains to the original query (ie the first part of the current query)

edited Apr 19, 2014 at 18:55

answered Apr 19, 2014 at 18:32

erosman

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4 Comments

MCGBra Over a year ago

See the update, please. Is there any problem receiving data from database?

erosman Over a year ago

Why was this answer marked down? At the time I posted, it corresponded to the (unedited) query. Query was edited afterwards. The mark-down process seems rather supercilious in addition to discouraging further participation.

MCGBra Over a year ago

Actually, I use to mark all up, just for thanking the response.

erosman Over a year ago

Thank you LIUFA & MCGBra ...TBH, I am becoming increasing hesitant in replying. I know it is not your fault :)

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