let file = event.target.files [0];
looks at the property values of this event.tartget.files [0] in the console, as shown in figure
then I want to know what type this attribute value is. The first habitual thinking is the object type, and then we"ll see how it looks like a function type. Here"s the point. I use
console.log (Object.prototype.toString.call (file) ="[object Object]"); / / false
console.log (Object.prototype.toString.call (file) ="[object Function]"); / / falseconsole.log (typeof file); / / object
curious, what kind of goods is this? Partners with research share their experiences