如何在事先不知道密钥的情况下检索所有 localStorage 项目？

我想显示之前编写的所有密钥和存储。 我的代码如下。我创建了一个函数（allStorage），但它不起作用。 我怎样才能做到这一点？

    function storeUserScribble(id) {
        var scribble = document.getElementById('scribble').innerHTML;
        localStorage.setItem('userScribble',scribble);
    }

    function getUserScribble() {
        if ( localStorage.getItem('userScribble')) {
            var scribble = localStorage.getItem('userScribble');
        }
        else {
            var scribble = 'You can scribble directly on this sticky... and I will also remember your message the next time you visit my blog!';
        }
        document.getElementById('scribble').innerHTML = scribble;
    }

    function clearLocal() {
        localStorage.clear();
        return false;
    }

    function allStorage() {
        var archive = [];
        for (var i = 0; i<localStorage.length; i++) {
            archive[i] = localStorage.getItem(localStorage.key(i));
        }
    }

ES2015+中最简单的方法是：

const items = { ...localStorage };