localStorage用法总结

先看一下localStorage自带的方法如下表：

名称	作用
clear	清空localStorage上存储的数据
getItem	读取数据
hasOwnProperty	检查localStorage上是否保存了变量x，需要传入x
key	读取第i个数据的名字或称为键值(从0开始计数)
length	localStorage存储变量的个数
propertyIsEnumerable	用来检测属性是否属于某个对象的
removeItem	删除某个具体变量
setItem	存储数据
toLocaleString	将（数组）转为本地字符串
valueOf	获取所有存储的数据

---

清空localStorage

localStorage.clear()    // undefined    
localStorage            // Storage {length: 0}

存储数据

localStorage.setItem("name","caibin") //存储名字为name值为caibin的变量
 
localStorage.name = "caibin"; // 等价于上面的命令
 
localStorage // Storage {name: "caibin", length: 1}

读取数据

localStorage.getItem("name") //caibin,读取保存在localStorage对象里名为name的变量的值
 
localStorage.name // "caibin"
 
localStorage.valueOf() //读取存储在localStorage上的所有数据
 
localStorage.key(0) // 读取第一条数据的变量名(键值)
 
//遍历并输出localStorage里存储的名字和值
 
for(var i=0; i<localStorage.length;i++){
 
console.log('localStorage里存储的第'+i+'条数据的名字为：'+localStorage.key(i)+',值为：'+localStorage.getItem(localStorage.key(i)));
 
}

删除某个变量

localStorage.removeItem("name"); //undefined
 
localStorage // Storage {length: 0} 可以看到之前保存的name变量已经从localStorage里删除了

检查localStorage里是否保存某个变量

// 这些数据都是测试的，是在我当下环境里的，只是demo哦～
 
localStorage.hasOwnProperty('name') // true
 
localStorage.hasOwnProperty('sex') // false

 

将数组转为本地字符串

var arr = ['aa','bb','cc']; // ["aa","bb","cc"]
localStorage.arr = arr //["aa","bb","cc"]
localStorage.arr.toLocaleString(); // "aa,bb,cc"

 

将JSON存储到localStorage里

var students = {
 
xiaomin: {
 
name: "xiaoming",
 
grade: 1
 
},
 
teemo: {
 
name: "teemo",
 
grade: 3
 
}
 
}
 
 
students = JSON.stringify(students); //将JSON转为字符串存到变量里
 
console.log(students);
 
localStorage.setItem("students",students);//将变量存到localStorage里
 
 
 
var newStudents = localStorage.getItem("students");
 
newStudents = JSON.parse(students); //转为JSON
 
console.log(newStudents); // 打印出原先对象