Using an or operator to assign a value to an object

Question

I have an identity function:

theIdentity = function(val) {
    return val;
 };

And a function that is going to reduce an array:

theReduce = function(collection, iterator, accumulator) {
    iterator = iterator || theIdentity;
};

I am having trouble understanding this line:

iterator = iterator || theIdentity;

I know it is supposed to check if the iterator is undefined and assign it as theIdentity if it is, but anymore insight would be appreciated.

it simply means if iterator is not false, null or undefined then use that, otherwise use theIdentity variable. — Abdul Mannan, Mar 22 '16 at 01:40

score -1 · Answer 1 · answered Mar 22 '16 at 01:21

-1

It is short-hand for:

if(iterator) 
   iterator = iterator
else 
   iterator = theIdentity;

answered Mar 22 '16 at 01:21

Andy T

1 Answers1