[TOC] > [參考](https://wangdoc.com/javascript/bom/storage.html#storagegetitem) ## 概述 localStorage生命周期是永久的，除非被清除，否則永久保存 而sessionStorage僅在當前會話下有效，關閉頁面或瀏覽器后被清除 ### 屬性與方法 ``` interface Storage { readonly length: number; clear(): void; getItem(key: string): string | null; key(index: number): string | null; removeItem(key: string): void; setItem(key: string, value: string): void; [name: string]: any; } ``` ## 實例 ### 三種寫法 ``` // 下面三種寫法等價 window.localStorage.foo = '123'; window.localStorage['foo'] = '123'; window.localStorage.setItem('foo', '123'); ···