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Introduction to JavaScript

Instance methods, by definition, require that you create an instance before you can use them. What if you want to call a method without an instance? That's where JavaScript libraries come in. Libraries contain methods that you can call without creating an instance.

One such collection contains mathematical methods, aptly named the `Math`

library.

Let's see how you call the `.random()`

method from the `Math`

library:

```
console.log(Math.random()); // random number between 0 and 1
```

In the example above, we called the `.random()`

method by appending the library name with a period, the name of the method, and opening (`(`

) and closing (`)`

) parentheses. This method returns a random number between 0 and 1. This code prints a random number between 0 and 1.

To generate a random number between 0 and 50, we could multiply this result by 50, like so:

```
Math.random() * 50;
```

The answer in the example above will most likely be a decimal. To ensure the answer is a whole number, JavaScript provides a built-in method called `Math.floor()`

. `Math.floor()`

takes a decimal number, and rounds down to the nearest whole number. You can use `Math.floor()`

to round a random number like this:

```
Math.floor(Math.random() * 50);
```

In this case:

`Math.random`

generates a random number between 0 and 1.- We then multiply that number by
`50`

, so now we have a number between 0 and 50. - Then,
`Math.floor`

rounds the number down to the nearest whole number.

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