When passing .eq() a variable containing an integer parsed out of a string the results are strange. In my case I was passing 0, 1 or 2 based on the values found in a string. When passing 0 and 2 I got expected results, when passing 1 I found that .eq(n).length == 2, which is very wrong.

I do not have a simple test case for this, but the fix is:

eq: function( i ) {

return this.slice( +i, +i + 1 );

},

The unary + forces i to be a number. I think there is no possible harm to this and it will save many people frustration. Technically, of course, it is user error.