ブレークポイントがない場合、Chrome 拡張機能のタブ情報が空のように表示されるのはなぜですか?

// Initialize an empty array
var fourmTabs = new Array();
// Initiate asynchronous `chrome.tabs.query` call
chrome.tabs.query({}, function (tabs) {
    // Iterate over returned tabs
    for (var i = 0; i < tabs.length; i++) {
        // Store tabs in array
        fourmTabs[i] = tabs[i];
    }
});

// Print tab URLs (before callback has been called)
for (var i = 0; i < fourmTabs.length; i++) {
    if (fourmTabs[i] != null)
        window.console.log(fourmTabs[i].url);
    else {
        window.console.log("??" + i);
    }
}

// Initialize an empty array
var fourmTabs = new Array();
// Initiate asynchronous `chrome.tabs.query` call
chrome.tabs.query({}, function (tabs) {
    // Update `fourmTabs` array
    for (var i = 0; i < tabs.length; i++) {
        fourmTabs[i] = tabs[i];
    }
    // Print tab URLs (after callback has been called)
    for (var i = 0; i < fourmTabs.length; i++) {
        if (fourmTabs[i] != null)
            window.console.log(fourmTabs[i].url);
        else {
            window.console.log("??" + i);
        }
    }
});