javascript - 把它变成一个 Javascript 闭包

Question

如何将其包装为 Javascript 闭包，使 var entryString 在 addEventListener 方法中工作

JSFiddle:http://jsfiddle.net/kboucheron/XVq3n/11/

    addButton = document.getElementById('addButton');
    var entryString = '';

addButton.addEventListener("click", function(e) {
    text = document.getElementById('listItem').value;
    var addItem = document.getElementById('output');
    entryString += '<li>';
    entryString += text;
    entryString += '</li>';
    var entry = '';
    entry.innerHTML = entryString; 
    addItem.appenChild(document.createTextNode(entry));
});

Answer 1

var addButton = document.getElementById('addButton');

addButton.addEventListener("click", function(e) {
    var text = document.getElementById('listItem').value;
    var addItem = document.getElementById('output');
    var entry = document.createElement("li");
    entry.innerHTML = text; 
    addItem.appendChild(entry);
});

JS fiddle : http://jsfiddle.net/XVq3n/13/