我在学习反应原生。当我看到XMLHttpRequest Base.js时,我想知道为什么语法如此奇怪?我从未见过。请帮忙。为什么可以将参数类型和返回类型添加到JavaScript?
class XMLHttpRequestBase {
\t UNSENT: number;
onload: ?Function;
responseHeaders: ?Object;
upload: ?{
onprogress?: (event: Object) => void;
};
constructor() {
}
_didUploadProgress(requestId: number, progress: number, total: number): void {
if (requestId === this._requestId && this.upload && this.upload.onprogress) {
var event = {
lengthComputable: true,
loaded: progress,
total,
};
this.upload.onprogress(event);
}
}
}
此文件的链接地址是https://github.com/facebook/react-native/blob/master/Libraries/Network/XMLHttpRequestBase.js
你想要什么?具体要求 – murli2308
只学,想了解 – kuangc