问在浏览器中处理“内存不足异常”时出错？

EN

var localStorageSpace = function(){
    var allStrings = '';
    for(var key in window.localStorage){
        if(window.localStorage.hasOwnProperty(key)){
            allStrings += window.localStorage[key];
        }
    }
    return allStrings ? 3 + ((allStrings.length*16)/(8*1024)) + ' KB' : 'Empty (0 KB)';
};

var storageIsFull = function () {
    var size = localStorageSpace(); // old size

    // try to add data
    var er;
    try {
         window.localStorage.setItem("test-size", "1");
    } catch(er) {}

    // check if data added
    var isFull = (size === localStorageSpace());
    window.localStorage.removeItem("test-size");

    return isFull;
}