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JavaScript can be inserted into a separate document and called when necessary.

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This is known as an external JavaScript file.

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You might recall we did this scene with our external C Ss file.

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Let's take a javascript function in our previous lesson and inserted into a new file.

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And when a copy of the entire function or sorry when it cut it I'm going to create a new file and paste

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it.

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Now I'm going to save this file as dog age J.S. J stands for JavaScript

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now in the head take we need to call this script

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and we'll do that by adding a source attribute to the script tag

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now we'll save this file and I'll previewed in my browser just to make sure it works.

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We can see that the script is working so we know that the javascript file was called successful

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there's a couple of advantages to using external JavaScript files.

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First it makes the HCM L code in JavaScript code easier to maintain cached JavaScript files.

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Also increase the speed at which the web page loads.