JavaScript: Get A Random Item From An Array

In one of my previous posts I’ve shown you how to get a random item from an array in PHP. Well, there is, of course, a way to do this in JavaScript as well. And it’s also very easy. Just declare someting like this:

<script>
var allItems = ['A', 'B', 'C', 1, 2, 3, 4, 5];
</script>


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Now you can access the values with their index (which starts at 0 for the first item).

$thirdItem = allItems[2];

Next we take a look at a simple way to get a random item from the array by using the Math.random() function for the index of our array. This function returns a random value between 0 and 1. So in order to get a random value within the range of our arrays indices, we must multiply Math.random() with the size of our array.

Math.random()*allItems.length;

O.K., now we have a number between 0 and 8 (the size of our array in our example). But it’s not an integer. So we’ll have to get an integer value by using the Math.floor() function.

Math.floor(Math.random()*allItems.length);

Yes, almost done 😉 Now we use our random index to get a random item from this JavaScript array:

<script>
var allItems = ['A', 'B', 'C',1, 2, 3, 4, 5];
var randomItem = allItems[Math.floor(Math.random()*allItems.length)];
alert(randomItem);
</script>

That’s it!


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