Question

I have the following line in my code:

var cart = $("#dynamo_shop_window .dynamo_content tbody .shop_cart").html();

However, I want the value of cart to be an empty string if there are no matching elements on the page, i.e:

!$("#dynamo_shop_window .dynamo_content tbody .shop_cart").size();

If this is the case, var cart = null;, well according to Chrome’s developer tools anyway.

To give it the empty string value, is there any reason why I should use cart = cart !== null ? cart : ''; after the above code instead of replacing the above code with:

var cart = $("#dynamo_shop_window .dynamo_content tbody .shop_cart").html() || '';

The .html() will never return 0 or any other false related statements.

Answer 1

No, not really. The double pipe operator falls through to the right-hand side whenever there’s a falsey value on the left-hand side, so one of undefined, null, NaN, 0 or "".

If, in all those cases, you want cart to be "": go for it. Use ||.