callback function & Promise

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callback function & Promise #15

Open at7211 opened 5 years ago

at7211 commented 5 years ago

callback function

function logAll(){
    logWord("A", function(){
        logWord("B", function(){
            logWord("C", function(){})
        })
    })
}

promise

優點：易讀、好維護


function logAll(){
    logWord("A")
    .then(function(){
        return logWord("B")
    })
    .then(function(){
        return logWord("C")
    })
}

// ES6寫法更簡潔
function logAll(){
    logWord("A")
    .then(() => logWord("B"))
    .then(() => logWord("C"))
}

at7211 commented 5 years ago

參考資料：JavaScript - Promise (2)