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oiii

async/await 新手提问

  •  
  •   oiii · Jul 25, 2018 · 3437 views
    This topic created in 2874 days ago, the information mentioned may be changed or developed.

    请问:类似下面结构的代码有什么优化的空间?刚开始使用 async/await,不知道用法是否正确?!

    async function showData(count = 0) {
        let data = await getData();
        if (data > 0.5) {
            if (count < 5) {
                return await showData();
            } else {
                return Promise.reject('无法获取');
            }
    
        } else {
            return Promise.resolve(data);
        }
    }
    
    function getData() {
        return new Promise((resolve) => {
            setTimeout(() => {
                resolve(Math.random());
            }, 1000);
        })
    }
    
    async function test() {
        try {
            let data = await showData();
            console.log(data);
        } catch (e) {
            console.log(e);
        }
    }
    
    test();
    
    3 replies    2018-08-08 13:08:20 +08:00
    oiii
        1
    oiii  
    OP
       Jul 25, 2018
    第五行应该是 return await showData(count + 1);
    MinonHeart
        2
    MinonHeart  
       Jul 25, 2018
    在 async 函数中
    return 时 await 不必要
    return Promise.resolve(data) = return data;
    return Promise.reject(msg) = throw msg
    e8c47a0d
        3
    e8c47a0d  
       Aug 8, 2018
    return Promise.reject('无法获取') 可以换成 throw '无法获取'
    return Promise.resolve(data); 可以换成 return data
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