我正在JavaScript中从File对象获取密钥,但是我不知道为什么对象的方法不能使用。
我尝试了Object.keys()和Object.getOwnPropertyNames()。为什么这些方法不起作用?
这里是示例:
var obj = {name:'my_name',id:1,value:'my_val'}
const file = document.getElementById('fileToUpload').files[0];
console.log('Object.keys(file)',Object.keys(file));
//Array []
console.log('Object.keys(obj)',Object.keys(obj));
//Array [3]
console.log('Object.getOwnPropertyNames(file)',Object.getOwnPropertyNames(file));
//Array []
console.log('Object.getOwnPropertyNames(obj)',Object.getOwnPropertyNames(obj));
//Array [3]
console.log('file.name',file.name);
//name.type
console.log('obj.name',obj.name);
//my_name
console.log('Object',file);
//File {...}
console.log('Object',obj);
//Object {...}
console.log('type',typeof file);
//object
console.log('type',typeof obj);
//object