JavaScriptSource

Instead of using the indexOf() method to check if an element is in the array, you can use the includes() method.

Use Array.prototype.slice(0, -1) to return all but the last element of the array.

This post demonstrates a common case where we show a loading indicator while an iframe is being loaded.

Remove leading and trailing whitespace from a string.

Compare the constructor property on the value with type to check if the provided value is of the specified type.