Question

I would like a function that compares to arrays of javascript strings, and saving the values that didnt match in to a new array. At the moment im using a nested jquery foreach. But i think there are better ways than this?

$.each(imagesInUploadsFolder, function(i, outervalue){
            $.each(imagesInDatabaseTable, function(i, innervalue){

                if(outervalue == innervalue){
                    //match in both arrays...
                } 

            });
        });

Answer 1

Here’s a way using a JSON object and no jQuery, although the $.inArray() should work fine:

var imagesInUploadsFolder = [
    '/path/to/img1.png',
    '/path/to/img2.png',
    '/path/to/img3.png'
];
var imagesInDatabaseTable = [
    '/path/to/img1.jpg',
    '/path/to/img2.png',
    '/path/to/img4.png'
];

var database_json = JSON.stringify(imagesInDatabaseTable);

for (var i = 0; i < imagesInUploadsFolder.length; i++) {
    console.log(imagesInUploadsFolder[i] + ' in ' + database_json);
    if (database_json.indexOf(imagesInUploadsFolder[i]) > -1) {
        console.log('In database: ' + imagesInUploadsFolder[i]);
    } else {
        console.log('Not in database: ' + imagesInUploadsFolder[i]);
    }
}

http://jsfiddle.net/7nJPW/1/

EDIT

Actually, the JSON method isn’t needed (?):

for (var i = 0; i < imagesInUploadsFolder.length; i++) {
    console.log(imagesInUploadsFolder[i] + ' in ' + imagesInDatabaseTable);
    if (imagesInDatabaseTable.indexOf(imagesInUploadsFolder[i]) > -1) {
        console.log('In database: ' + imagesInUploadsFolder[i]);
    } else {
        console.log('Not in database: ' + imagesInUploadsFolder[i]);
    }
}

http://jsfiddle.net/7nJPW/2/