Question

I am kind of confusing about the jquery.map function.

I have an array say myArray = ["1", 3, "a", 5].

Can I use $.map().get().join(',') to get result of [1, 3, 5];

$(myArray).map(function() { 
    if (!isNaN(this)){  
        return this
    }       
}).get().join(',');

the above code return ["1","3","a","5"]

http://jsfiddle.net/kkgian/khurZ/

TIA

Answer 1

.map() does not alter the original array. Because your code does not capture the value returned, you’re just throwing it away.

Use the (poorly-named) $.grep function instead of .map(). Thanks to the invert argument, you don’t even have to use an anonymous function; you can use isNaN directly as the predicate.

var filteredArray = $.grep(myArray, isNaN, true);

http://jsfiddle.net/mattball/nzeBZ/

N.B. isNaN('1') returns false because '1' is a string that can be reasonably coerced to a number. If that’s not acceptable, use a better filter predicate. It’s a little unclear if you actually want an array of numbers, or just the string '[1, 3, 5]', however.