# Get a Random Element from an Array using JavaScript

To get a random element from an array, we can use the built-in function `Math.random()`. The `Math.random()` function generates a random floating-point number between 0 and 1.

So, if we generate a random number between 0 and the array’s last index, we can get its elements randomly by using this number as the array index.

See the following example:

```const arr = ['apple', 'mango', 'orange', 'banana'];

// Generate random number from 0 to 3
let randomIndex = Math.floor(Math.random()*arr.length);

// Get random item
let randomItem = arr[randomIndex];

console.log(randomItem);
// Output: mango```

In the above example, we are first generating a random floating-point number between 0 and 1 using the `Math.random()` function. Please note that it can return 0 but can never return 1.

```console.log(Math.random());  // 0.35
console.log(Math.random());  // 0.94
console.log(Math.random());  // 0.54```

Now, these random numbers should be in the range of 0 to arr.length-1. In our case from 0 to 3.

Therefore, we have to multiply these randomly generated numbers with the array’s length:

```const arr = ['apple', 'mango', 'orange', 'banana'];

console.log(Math.random()*arr.length);  // 0.03
console.log(Math.random()*arr.length);  // 2.46
console.log(Math.random()*arr.length);  // 3.69
```

But the array’s index can never be a floating-point number. It must be an integer from 0 to the array’s length.

Therefore, we have to convert these floating-point numbers into integer values. To achieve that we can use the `Math.floor()` function.

The `Math.floor()` function rounds down the given number to its nearest integer. If the number is already an integer value, it makes no changes.

For example:

```console.log(Math.floor(4.98));   // 4
console.log(Math.floor(4.43));   // 4
console.log(Math.floor(4));      // 4```

In our case, the `Math.floor()` function will round down the randomly generated number to its nearest integer value.

```const arr = ['apple', 'mango', 'orange', 'banana'];

console.log(Math.floor(Math.random()*arr.length));  // 2
console.log(Math.floor(Math.random()*arr.length));  // 0
console.log(Math.floor(Math.random()*arr.length));  // 1
```

We can use these randomly generated numbers as the array index to get the elements randomly.