javascript - JavaScript本地存储

如何检查本地存储值是否为空？例如..

localStorage.setItem('favoriteflavor','');

var taste = localStorage.getItem('favoriteflavor');

if(taste == null){
   console.log('favoriteflavor is null');
}
else {
   console.log('favoriteflavor is NOT null');
}

这是最有意义的，但我没有得到任何结果。我也尝试过

 if(localStorage['favoriteflavor'] == 'null'){
   console.log('favoriteflavor is null');
 }

http://jsfiddle.net/AwsyE/6/

最佳答案

如果将favoriteflavor设置为空字符串，则应检查它是否为空字符串，而不是其他内容

localStorage.setItem('favoriteflavor','');
var taste = localStorage.getItem('favoriteflavor');
if(taste == ''){
   console.log('favoriteflavor is empty');
}
else{
   console.log('favoriteflavor is NOT empty');
}

或者，如果要删除favoriteflavor，则可以将其检查为null

localStorage.setItem('favoriteflavor','chocolate');
delete localStorage['favoriteflavor'];
// or use localStorage.removeItem('favoriteflavor');

var taste = localStorage.getItem('favoriteflavor');

if(taste == null){

   console.log('favoriteflavor is null');

}
else
{
   console.log('favoriteflavor is NOT null');
}

http://jsfiddle.net/mowglisanu/AwsyE/10/