Javascript 本地存储变量被锁定为false

我试图在本地存储中切换真/假变量

console.log("Toggling...");
console.log("Current:" + localStorage.item);
console.log("Current is being changed to: " + !localStorage.item);
localStorage.item = !localStorage.item;
console.log("Current " + localStorage.item);

它的作用是：

首轮

 Toggling...
    (index):31 Current:undefined
    (index):32 Current is being changed to: true
    (index):34 Current true

第二轮

Toggling...
(index):31 Current:true
(index):32 Current is being changed to: false
(index):34 Current false

后续运行

Toggling...
(index):31 Current:false
(index):32 Current is being changed to: false
(index):34 Current false

---

为什么我的变量没有变回true？

您不希望像这样直接在

localStorage

上设置属性。相反，使用

setItem（key，value）

，

getItem（key）

，和

removietem（key）

示例来自：

以下代码段访问当前域的本地存储对象，并使用Storage.setItem（）向其添加数据项

读取localStorage项的语法如下所示：

var cat = localStorage.getItem('myCat');

localStorage.removeItem('myCat');

删除localStorage项的语法如下所示：

var cat = localStorage.getItem('myCat');

localStorage.removeItem('myCat');

这样的话：

console.log("Toggling...");
console.log("Current:" + localStorage.getItem('item'));
console.log("Current is being changed to: " + !localStorage.getItem('item'));
localStorage.setItem('item', !localStorage.getItem('item'));
console.log("Current " + localStorage.getItem('item'));

---

实际上，您的布尔值在localStorage上存储为字符串

本地存储的类型。项将返回“字符串”

从这一点开始，长度>0的字符串被认为是真实的，即使它的值设置为

“false”

如果使用以下选项，也会发生这种情况：

考虑：

• 从本地存储中删除该项，而不是检查其负布尔值
• 使用JSON.parse（）： localStorage.item=！parse（localStorage.item）

有关其他信息，请选中

您可以使用JSON.parse（）将其解析为boolen值：

console.log("Toggling...");
console.log("Current:" + localStorage.item);
console.log("Current is being changed to: " + !JSON.parse(localStorage.item));
localStorage.item = !JSON.parse(localStorage.item);
console.log("Current " + localStorage.item);

console.log("Toggling...");
console.log("Current:" + localStorage.item);
console.log("Current is being changed to: " + !JSON.parse(localStorage.item));
localStorage.item = !JSON.parse(localStorage.item);
console.log("Current " + localStorage.item);