CODEWITHSUNDEEP
javascriptjqueryjsonajaxconcatenation
Alexandre Rivara
Alexandre Rivara

Reputation: 93

How to concat a variable to the name of another with web languages

I lack some basics in these languages so it might be an easy question.

I receive an json encoded array of object from an ajax call. At the begining of it, I add some elements I need :

array_unshift($data, array('nbr' => 6,'Col1' => 'Company name', 
'Col2' => 'Email','Col3' => 'Adress','Col4' => 'City',
'Col5' => 'Code','Col6' => 'Country));

In the success:function(msg) of the ajax I want to iterate through these elements to make them the headers of a table :

var qtt=msg[0].nbr;
$foo='<table>';
for (var i = 1; i<qtt; i++) {
    $foo=$foo+'<th>'+msg[i].Col+i+'</th>';
}
$foo=$foo+'</table>;

I want to access the i'th element of msg and I know it is named 'Col'+i. To me, it looks simple and difficult at the same time.

I just don't know how to do this, no idea. Any help is welcome.

Edit : With firebug I could retreive the answer of the ajax call. If it can help you here it is (the element are in french but it is exactly what I was talking about previously) :

[{"nbr":6,"Col1":"Nom soci\u00e9t\u00e9","Col2":"Email","Col3":"Adresse",
"Col4":"Ville","Col5":"Code postal","Col6":"Pays"},
{"Soc_Nom":"foo1","Soc_Email":"bar1","Soc_Adresse":"foobar1", "Vil_Nom":
"Foofoo1","Vil_Code_Postal":"1000","Pys_Nom":"Belgique"},{"Soc_Nom":
"Foo2","Soc_Email":"Bar2","Soc_Adresse":"foobar2","Vil_Nom":"Foofoo2",
"Vil_Code_Postal":"2000","Pys_Nom":"Belgique"}]

Ansewer : No need to iterate through msg[] since all the info I wanted to access was in msg[0].

Using msg[0]['Col'+i] works perfectly.

Upvotes: 0

Views: 33

Answers (1)

ps2goat
ps2goat

Reputation: 8495

If you're trying to access a property name dynamically, you can use an indexer with the property name as a string:

$foo=$foo+'<th>'+msg[i].Col+i+'</th>';

becomes 

$foo=$foo+'<th>'+msg[i]['Col' + i]+'</th>';

msg[i].Col + i (your original code) is looking for a property named Col and trying to add the value of Col to the value of i.

The second example is building a dynamic property name 'Col' + i, and using brackets to access a property of that name on the msg[i] object.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Property_Accessors

Upvotes: 1

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