sessionStorage.getItem（'key'）可以触发异常吗？ 隐身模式？ 任何旧的手机浏览器？

Question

I'm curious if sessionStorage.getItem('mytestdata') ever can trigger an exception. I'm NOT talking about

localStorage.setItem('key', 'value')

but rather about

sessionStorage.getItem('key')

Thank you.

Answer 1

Yes, but just if you are using a very old version of web browser, not if a key doesn't exists. You can check compatibility here https://developer.mozilla.org/es/docs/Web/API/Window/sessionStorage

Answer 2

If any item not set in localstorage then you need to check it by typeof != 'undefined'

if(typeof sessionStorage.getItem('key') !== null){
  //The `key` is set in the `localStorage`
}

if(typeof sessionStorage.getItem('key') != 'undefined'){
   //The `key` and `value` both are set in the `localStorage`    
}