Javascript Shorthand - What Does the '||' Operator Mean When Used in an Assignment? [duplicate]

Question

I just took a look at this answer, and I noticed the following line of javascript code:

hrs = (hrs - 12) || 12;

My Question:

What does the '||' operator mean when used in an assignment?

Answer 1

In this case, the code assigns 12 to hrs if hrs-12 = 0 (as JavaScript sees it, 0 = false).

More generally, it assigns the latter value to the variable if the former value evaluates to 0, the empty string, null, undefined, etc.