---
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);
}
}
```