Develop Reference

Mongoose update on a string variable not working? [duplicate]

It's difficult to explain the case by words, let me give an example:
var myObj = {
'name': 'Umut',
'age' : 34
};
var prop = 'name';
var value = 'Onur';
myObj[name] = value; // This does not work
eval('myObj.' + name) = value; //Bad coding ;)
How can I set a variable property with variable value in a JavaScript object?

myObj[prop] = value;
That should work. You mixed up the name of the variable and its value. But indexing an object with strings to get at its properties works fine in JavaScript.

myObj.name=value
or
myObj['name']=value (Quotes are required)
Both of these are interchangeable.
Edit: I'm guessing you meant myObj[prop] = value, instead of myObj[name] = value. Second syntax works fine: http://jsfiddle.net/waitinforatrain/dNjvb/1/

You can get the property the same way as you set it.
foo = {
bar: "value"
}
You set the value
foo["bar"] = "baz";
To get the value
foo["bar"]
will return "baz".

You could also create something that would be similar to a value object (vo);
SomeModelClassNameVO.js;
function SomeModelClassNameVO(name,id) {
this.name = name;
this.id = id;
}
Than you can just do;
var someModelClassNameVO = new someModelClassNameVO('name',1);
console.log(someModelClassNameVO.name);

simple as this
myObj.name = value;

When you create an object myObj as you have, think of it more like a dictionary. In this case, it has two keys, name, and age.
You can access these dictionaries in two ways:
Like an array (e.g. myObj[name]); or
Like a property (e.g. myObj.name); do note that some properties are reserved, so the first method is preferred.
You should be able to access it as a property without any problems. However, to access it as an array, you'll need to treat the key like a string.
myObj["name"]
Otherwise, javascript will assume that name is a variable, and since you haven't created a variable called name, it won't be able to access the key you're expecting.

You could do the following:
var currentObj = {
name: 'Umut',
age : 34
};
var newValues = {
name: 'Onur',
}
Option 1:
currentObj = Object.assign(currentObj, newValues);
Option 2:
currentObj = {...currentObj, ...newValues};
Option 3:
Object.keys(newValues).forEach(key => {
currentObj[key] = newValues[key];
});

Getting data from an object with a generated key

Lets assume I have an object like this.
var foo = {
"dfsghasdgsad":{
"name":"bob",
"age":"27"
}
};
foo will always have just one object but the key is generated. How do I retrieve "bob" and "27" in a situation where I won't know what the generated key name will be?

Use Object.keys:
var key = Object.keys(foo)[0];
var name = foo[key].name;

Use Object.keys to get a list of the keys:
var name = foo[Object.keys(foo)[0]].name;

Javascript setter and getter with key for object

I have an object in a variable var o={};
I want to do something like what .push() method doing in array for my object.
JS code:
// Array:
var ar=[];
ar.push('omid');
ar.push('F');
var got=ar[1];
// above code is standard but not what I'm looking for !
/*-------------------------------------*/
// Object:
var obj={};
/* obj.push('key','value'); // I want do something like this
var got2=obj.getVal('key'); // And this
*/
Is this possible at all ?

var obj = {}
// use this if you are hardcoding the key names
obj.key = 'value'
obj.key // => 'value'
// use this if you have strings with the key names in them
obj['key2'] = 'value'
obj['key2'] // => 'value'
// also use the second method if you have keys with odd names
obj.! = 'value' // => SyntaxError
obj['!'] = 'value' // => OK

Since Object-Literals use a Key->Value model, there is no JS method to "push" a value.
You can either use Dot Notation:
var Obj = {};
Obj.foo = "bar";
console.log(Obj);
Or Bracket Notation:
var Obj = {},
foo = "foo";
Obj[foo] = "bar";
Obj["bar"] = "foo";
console.log(Obj);
Consider reading https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_Objects, as arming yourself with this knowledge will be invaluable in the future.

Here is some javascript magic that makes it work.
Take a look.
var obj = {};
Object.defineProperty(obj,'push',{
value:function(x,y){
this[x]=y;
}
});
obj.push('name','whattttt'); <<<this works!!!
obj;
//{name:'whattttt'}
obj.name or obj['name']..
//whattttt
The reason i defined .push function using Object.defineProperty because i didn't want it to show up as a property of object. So if you have 3 items in object this would have always been the 4th one. And mess up the loops always. However, using this method. You can make properties hidden but accessible.
Though i don't know why you would use this method when there is already a easy way to do it.
to assign a value do this
obj.variable = 'value';
if value key is number or weird do this...
obj[1] = 'yes';
to access number or weird name you also do that
obj[1];
and finally to assign random keys or key that has been generated in code, not hard coded, than use this form too.
var person= 'him';
obj[him]='hello';

javascript get json inner value

Let's I have next object
var o = { "foo" : {"bar" : "omg"} };
I can get value of key foo using
o["foo"] // return {"bar" : "omg"}
and I can get value of key bar inside foo using
o["foo"]["bar"] // return "omg"
Can I get value of key bar inside foo using brackets [] single time.
Somethong like
o["foo.bar"] // not working(
or
o["foo/bar"] // not working(

It is fairly common to create a getter function to do something like this. From the comment:
I have object o and string 'foo.bar', and i want get "omg".
var getProp = function (theObject, propString) {
var current = theObject;
var split = propString.split('.');
for (var i = 0; i < split.length; i++) {
if (current.hasOwnProperty(split[i])) {
current = current[split[i]];
}
}
return current;
};
http://jsfiddle.net/MXu2M/
Note: this is a thrown together example, you'd want to bullet proof and buff it up before dropping it on your site.

No, you must use o["foo"]["bar"] because it's an object inside another object. If you want to access it with "foo.bar", it means you must create the first object like this:
var o = {"foo.bar": "omg"}

o["foo.bar"] or o["foo/bar"] are not valid for your example. You could use this notation that is cleaner:
var bar = o.foo.bar // bar will contain 'omg'

there is a way, but I'm not sure this is what you asked for:
eval("o.foo.bar");
it is dangerous though, and doesn't use [] , but if what you want is to use a string for accessing any object it works

Unfortunately, you can only use o["foo"]["bar"] or o.foo.bar

Change key in js associative array

If I have:
var myArray = new Array();
myArray['hello'] = value;
How can I change the key 'hello' to something else?
Something like this would work.
var from = 'hello',
to = 'world',
i, value = myArray[from];
for( i in myArray )
if( i == from ) myArray.splice( i, 1 );
myArray[to] = value;
But is there a native function or a better way to do it?
edit:
Due to the lack of associative arrays in js, what I want to do modify the property name of an object as efficiently as possible.

In JavaScript there is no such thing as associative Array. Objects can be used instead:
var myHash = new Object();
or
var myHash = {};
replace can be done like this:
myHash["from"] = "value";
myHash["to"] = myHash["from"];
delete myHash["from"];
but the preferred way to write it:
myHash.from = "value";
myHash.to = myHash.from;
delete myHash.from;

You can't really "change" the property name, but you can always assign a property value to a new name, and then delete the original one.
myArray['world'] = myArray.hello;
delete myArray.hello;
Also, you're working with an Array instance but using it as a simple object; everything you're doing would work just as well with:
var myArray = {};
The "splice()" you're attempting in the code posted won't work, because it's only for the actual integer-indexed array properties, and not the named properties.
That "delete" doesn't really delete a property really doesn't matter. The "undefined" value is what you get when you check an object for a property and there's no such property.