adding to existing obj using JSON

[Andrew Poulos]

There's an object:

foo = new Object();

and a property called 'bar' with a value of 1 is to be added to it using
JSON. If I try the following it only demonstrates my ignorance:

var str = "{foo:{bar:1}}";
eval(str);
alert(foo.bar) // gives undefined

Could someone please explain what I'm doing wrong here?


Andrew Poulos

 

[RobG]

There's an object:

foo = new Object();

and a property called 'bar' with a value of 1 is to be added to it using
JSON. If I try the following it only demonstrates my ignorance:

var str = "{foo:{bar:1}}";
eval(str);
alert(foo.bar) // gives undefined

What you are trying to do is the equivalent of initialising a variable
with an object literal:

var foo = {bar : 1};


Presuming you are using AJAX or similar to return JSONtext, then
depending on how you want do it, you can do:

var JSONtext = '{bar:1}';
var foo = eval( '(' + JSONtext + ')' );

or

eval( 'var foo = ' + JSONtext );


Maybe you want to do:

var JSONtext = 'var foo = {bar:1}';
eval(JSONtext);


Over to you...