--- id: 587d7daf367417b2b2512b7d title: Iterate Over All Properties challengeType: 1 forumTopicId: 301320 --- ## 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. ```js 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: ```js 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); - text: The prototypeProps array should include "numLegs". testString: assert(prototypeProps.indexOf('numLegs') !== -1); - text: You should solve this challenge without using the built in method Object.keys(). testString: assert(!/\Object.keys/.test(code)); ```
## Challenge Seed
```js function Dog(name) { this.name = name; } Dog.prototype.numLegs = 4; let beagle = new Dog("Snoopy"); let ownProps = []; let prototypeProps = []; // Only change 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); } } ```