---
id: 587d7daf367417b2b2512b7d
title: Iterate Over All Properties
challengeType: 1
---
## Description
You have now seen two kinds of properties: own properties and prototype properties. Own properties are defined directly on the object instance itself. And prototype properties are defined on the prototype.
function Bird(name) {
this.name = name; //own property
}
Bird.prototype.numLegs = 2; // prototype property
let duck = new Bird("Donald");
Here is how you add duck's own properties to the array ownProps and prototype properties to the array prototypeProps:
let ownProps = [];
let prototypeProps = [];
for (let property in duck) {
if(duck.hasOwnProperty(property)) {
ownProps.push(property);
} else {
prototypeProps.push(property);
}
}
console.log(ownProps); // prints ["name"]
console.log(prototypeProps); // prints ["numLegs"]
## Instructions
Add all of the own properties of beagle to the array ownProps. Add all of the prototype properties of Dog to the array prototypeProps.
## Tests
```yml
tests:
- text: The ownProps array should include "name".
testString: assert(ownProps.indexOf('name') !== -1, 'The ownProps array should include "name".');
- text: The prototypeProps array should include "numLegs".
testString: assert(prototypeProps.indexOf('numLegs') !== -1, 'The prototypeProps array should include "numLegs".');
- text: Solve this challenge without using the built in method Object.keys().
testString: assert(!/\Object.keys/.test(code), 'Solve this challenge without using the built in method Object.keys().');
```
## Challenge Seed
```js
function Dog(name) {
this.name = name;
}
Dog.prototype.numLegs = 4;
let beagle = new Dog("Snoopy");
let ownProps = [];
let prototypeProps = [];
// Add your code below this line
```
## Solution
```js
function Dog(name) {
this.name = name;
}
Dog.prototype.numLegs = 4;
let beagle = new Dog("Snoopy");
let ownProps = [];
let prototypeProps = [];
for (let prop in beagle) {
if (beagle.hasOwnProperty(prop)) {
ownProps.push(prop);
} else {
prototypeProps.push(prop);
}
}
```