通过HTML5和JavaScript中的localStorage循环 [英] Looping through localStorage in HTML5 and JavaScript

问题描述

所以，我认为我可以像普通对象一样循环访问localStorage，因为它具有一定的长度。我怎样才能遍历这个？

  localStorage.setItem（1，'Lorem'）; 
 localStorage.setItem（2，'Ipsum'）; 
 localStorage.setItem（3，'Dolor'）; 
  

如果我执行 localStorage.length 它返回 3 ，这是正确的。因此，我假设中的循环可以正常工作。

我在想这样的事情： / p>

  for（x in localStorage）{
 $（'body'）。append（localStorage [x]）; 
} 
  

但无济于事。任何想法？

我的另一个想法是类似于

  localStorage.setItem（1，'Lorem | Ipsum | Dolor'）
 var split_list = localStorage.getItem（1）.split（'|'）; 
  

其中 for ... in 确实有效。

解决方案

你可以使用 key 方法。 localStorage.key（index）返回 index th键（订单是实现定义的，但在您添加或之前是常量删除键）。

  for（var i = 0; i< localStorage.length; i ++）{
 $ （ '主体'）附加（localStorage.getItem（localStorage.key（I）））; 
 
 
 
 
 
 $ b 
如果顺序很重要，你可以存储一个JSON序列化的数组：
  localStorage.setItem（words，JSON.stringify（[Lorem，Ipsum，Dolor]））; 
  
规范草案声称任何支持结构化克隆可以是一个值。但是，这似乎还没有得到支持。编辑：加载数组，然后存储：
  var words = JSON.parse（localStorage.getItem（words））; 
 words.push（hello）; 
 localStorage.setItem（words，JSON.stringify（words））; 
  
 
So, I was thinking I could just loop through localStorage like a normal object as it has a length. How can I loop through this?
localStorage.setItem(1,'Lorem');
localStorage.setItem(2,'Ipsum');
localStorage.setItem(3,'Dolor');
If I do a localStorage.length it returns 3 which is correct. So I'd assume a for...in loop would work.

I was thinking something like:
for (x in localStorage){
    $('body').append(localStorage[x]);
}
But no avail. Any ideas?

The other idea I had was something like
localStorage.setItem(1,'Lorem|Ipsum|Dolor')
var split_list = localStorage.getItem(1).split('|');
In which the for...in does work.
解决方案
You can use the key method.  localStorage.key(index) returns the indexth key (the order is implementation-defined but constant until you add or remove keys).
for (var i = 0; i < localStorage.length; i++){
    $('body').append(localStorage.getItem(localStorage.key(i)));
}
If the order matters, you could store a JSON-serialized array:
localStorage.setItem("words", JSON.stringify(["Lorem", "Ipsum", "Dolor"]));
The draft spec claims that any object that supports structured clone can be a value.  But this doesn't seem to be supported yet.

EDIT: To load the array, add to it, then store:
var words = JSON.parse(localStorage.getItem("words"));
words.push("hello");
localStorage.setItem("words", JSON.stringify(words));


                        
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