Question

In an example where eq() function is used, it was used as eq(“+index+”)

I haven’t seen syntax like this before. What does “+” sign on both sides mean? How is it different from eq(index)?

Thank you!

Answer 1

In jQuery, eq refers to two slightly different things: .eq, the function, and :eq, the selector.

The function version is chained onto a jQuery object, so you’d see examples like:

$(".whatever").eq(index)

Whereas the other form is used as part of the selector string, so you’ll see people concatenate the index with the rest of the string:

$(".whatever:eq(" + index + ")")

For performance reasons (and better readability in many cases), the jQuery documentation recommends the first form, the .eq function.