Getting the object's property name [duplicate]

i is the name.

for(var name in obj) { alert(name); var value = obj[name]; alert(value); } 

So you could do:

seperateObj[i] = myObject[i]; 

Disclaimer I misunderstood the question to be: "Can I know the property name that an object was attached to", but chose to leave the answer since some people may end up here while searching for that.

No, an object could be attached to multiple properties, so it has no way of knowing its name.

var obj = {a:1}; var a = {x: obj, y: obj} 

What would obj's name be?

Are you sure you don't just want the property name from the for loop?

for (var propName in obj) { console.log("Iterating through prop with name", propName, " its value is ", obj[propName]) } 

you can easily iterate in objects

eg: if the object is var a = {a:'apple', b:'ball', c:'cat', d:'doll', e:'elephant'};

Object.keys(a).forEach(key => { console.log(key) // returns the keys in an object console.log(a[key]) // returns the appropriate value }) 

for direct access a object property by position... generally usefull for property [0]... so it holds info about the further... or in node.js 'require.cache[0]' for the first loaded external module, etc. etc.

Object.keys( myObject )[ 0 ] Object.keys( myObject )[ 1 ] ... Object.keys( myObject )[ n ] 

Other than "Object.keys( obj )", we have very simple "for...in" loop - which loops over enumerable property names of an object.

const obj = {"fName":"John","lName":"Doe"}; for (const key in obj) { //This will give key console.log(key); //This will give value console.log(obj[key]); }

IN ES5

E.G. you have this kind of object:

var ELEMENTS = { STEP_ELEMENT: { ID: "0", imageName: "el_0.png" }, GREEN_ELEMENT: { ID: "1", imageName: "el_1.png" }, BLUE_ELEMENT: { ID: "2", imageName: "el_2.png" }, ORANGE_ELEMENT: { ID: "3", imageName: "el_3.png" }, PURPLE_ELEMENT: { ID: "4", imageName: "el_4.png" }, YELLOW_ELEMENT: { ID: "5", imageName: "el_5.png" } }; 

And now if you want to have a function that if you pass '0' as a param - to get 'STEP_ELEMENT', if '2' to get 'BLUE_ELEMENT' and so for

function(elementId) { var element = null; Object.keys(ELEMENTS).forEach(function(key) { if(ELEMENTS[key].ID === elementId.toString()){ element = key; return; } }); return element; } 

This is probably not the best solution to the problem but its good to give you an idea how to do it.

Cheers.

To get the property of the object or the "array key" or "array index" depending on what your native language is..... Use the Object.keys() method.

Important, this is only compatible with "Modern browsers":

So if your object is called, myObject...

var c = 0; for(c in myObject) { console.log(Object.keys(myObject[c])); } 

Walla! This will definitely work in the latest firefox and ie11 and chrome...

Here is some documentation at MDN https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys

As of 2018 , You can make use of Object.getOwnPropertyNames() as described in Developer Mozilla Documentation

const object1 = { a: 1, b: 2, c: 3 }; console.log(Object.getOwnPropertyNames(object1)); // expected output: Array ["a", "b", "c"] 

Using Object.keys() function for acquiring properties from an Object, and it can help search property by name, for example:

const Products = function(){ this.Product = "Product A"; this.Price = 9.99; this.Quantity = 112; }; // Simple find function case insensitive let findPropByName = function(data, propertyName){ let props = []; Object.keys(data).forEach(element => { return props.push(element.toLowerCase()); }); console.log(props); let i = props.indexOf(propertyName.toLowerCase()); if(i > -1){ return props[i]; } return false; }; // calling the function let products = new Products(); console.log(findPropByName(products, 'quantity')); 

When you do the for/in loop you put up first, i is the property name. So you have the property name, i, and access the value by doing myObject[i].

These solutions work too.

// Solution One function removeProperty(obj, prop) { var bool; var keys = Object.keys(obj); for (var i = 0; i < keys.length; i++) { if (keys[i] === prop) { delete obj[prop]; bool = true; } } return Boolean(bool); } //Solution two function removeProperty(obj, prop) { var bool; if (obj.hasOwnProperty(prop)) { bool = true; delete obj[prop]; } return Boolean(bool); } 

Quick & dirty:

function getObjName(obj) { return (wrap={obj}) && eval('for(p in obj){p}') && (wrap=null); }