js笔试题：请使用Promise封装下面的异步方法request,使之可以同步调用

Question

//request的用法如下
request(url,(response) => {
  console.log(response);
});

//请使用request实现同步方法requestSync(url)
//const response = await requestSync(url);

function requestSync(url) {

}

Answer 1

function requestSync(url){
        return new Promise((resolve,reject)=>{
            request(url,(response) => {
              resolve(response);
            });
        });
    }
    
    
    可以这样调用 
    requestSync('url').then(res => {
        console.log(res)
    })
    
    当然如果为了好看可以用async 和 await
    async dosomething(){
     const res =await requestSync(url)
     console.log(res)
    }

Answer 2

用promise把封装request一个函数，配合Generator和yield去调用，具体怎么使用看这里http://es6.ruanyifeng.com/#do...

Answer 3

function requestSync(url) {
    return new Promise(function(resolve) {
        request(url, (response) => {
            resolve(response);
        });
    });
}

这样，只要函数返回 Promise 对象就可以 await 调用，如：

const res = await requestSync(url);
console.info(res);

Answer 4

function requestAsync(url){
    return new Promise(res => {
        request(url, res);
    });
}