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Welcome back in the previous video we saw that javascript finds methods and properties on an object

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by working up the prototype chain.

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We also saw that the prototype property is a great place to put properties and methods that we want

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to share amongst all objects created from that constructor function.

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Let's take a look at an example and see why placing methods and properties on the prototype object is

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very efficient.

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In this example we're attaching a method called Say hi onto the object created from the person constructor

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function.

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Now this will work totally fine.

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But let's think a bit more about what we just did.

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Every time that a person object is created we have to define this function on that object.

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So when we make one million objects from the constructor we're adding the same high property.

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One million times that doesn't seem very efficient.

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It would be nice if we could just define it once and have it accessible from every object created from

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the person constructor and that is exactly what placing methods on the prototype property lets us do

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in the example below.

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We've refactored our code from above so that we only define the say high function once this code is

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much more efficient and makes use of best practices with object oriented programming in javascript.

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Now it's your turn.

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Create a constructor function for a vehicle.

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Every object created from this constructor function should have a make model and year property each

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object should also have a property called is running which should be equal to false.

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Every object created from the vehicle constructor should have a function called Turn on which changes

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the is running property for that object to true every object created from a local constructor should

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also have a function called Turn off which changes the is running property to False.

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Finally every object created from the vehicle constructor should have a method called honk which returns

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the string beep.

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Only if the is running property on that object is true.

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Think about where each of these properties and methods should be define for the vehicle objects created

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from the constructor function and will go over a solution in the next video.

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Good luck