chrome.storage.sync.get("cake", function(result) {
    alert(result["cake"]);
});

var keys = new Array("cake", "pie", "squirrel");
$.each(keys, function() {
    var key = $('<div>').append(this).html(); // ignore this line
    chrome.storage.sync.get(key, function(result) {
        alert(result[key]);
    });
});

var keys = new Array("cake", "pie", "squirrel");
$.each(keys, function() {
    var key = $('<div>').append(this).html(); // ignore this line

    chrome.storage.sync.get(key, function(result) {
        var key;
        for (key in result) {}

        alert(result[key]);
    });
});

var keys = ["cake", "pie", "squirrel"];
chrome.storage.sync.get(keys,function(result){
    keys.forEach(function(key){
        alert(result[key]);
    })
});