Question

任何人都知道“此功能需要“严格使用”编译指示”的原因。 JSLinting此代码时出现错误？我可以通过添加“ use strict”来解决此问题；到我所有的功能，但我宁愿知道如何一起解决它。干杯！

/*jslint browser: true, devel: true,  white: true, long: true, for: true*/
/*eslint-env browser*/
/*eslint 'no-console':0*/

var metronomebutton = document.querySelector("#playMetronome");
var stopmetronomebutton = document.querySelector("#stopMetronome");
var playing;
var audiobutton1 = document.querySelector("#c1Button");
var audiobutton2 = document.querySelector("#d1Button");
var audiobutton3 = document.querySelector("#e1Button");
var audiobutton4 = document.querySelector("#f1Button");
var audiobutton5 = document.querySelector("#g1Button");
var audiobutton6 = document.querySelector("#a1Button");
var audiobutton7 = document.querySelector("#b1Button");
var c1 = new Audio("Piano/c1.mp3");
var d1 = new Audio("Piano/d1.mp3");
var e1 = new Audio("Piano/e1.mp3");
var f1 = new Audio("Piano/f1.mp3");
var g1 = new Audio("Piano/g1.mp3");
var a1 = new Audio("Piano/a1.mp3");
var b1 = new Audio("Piano/b1.mp3");
var metronome = new Audio("Piano/tick.wav");
var artiesten = ["Mozart", "Beethoven", "Chopin"];
var i;



function dagartiest(artiesten)  {               //kiest een random artiest uit de array

    return artiesten[Math.floor(Math.random()* artiesten.length)];

}

for (i = 0; i < artiesten.length; i+=1) {       //Laat alle artiesten uit de array in de console zien

    console.log(artiesten[i]);
}

function playAudio() {                          //speel de noot c1

    c1.play();
    c1.currentTime =0;
}

function playAudio1() {                         //speel de noot d1

    d1.play();
    d1.currentTime =0;
}

function playAudio2() {                         //speel de noot e1

    e1.play();
    e1.currentTime =0;
}

function playAudio3() {                         //speel de noot f1

    f1.play();
    f1.currentTime =0;
}

function playAudio4() {                         //speel de noot g1

    g1.play();
    g1.currentTime =0;
}

function playAudio5() {                         //speel de noot a1

    a1.play();
    a1.currentTime =0;
}

function playAudio6() {                         //speel de noot b1

    b1.play();
    b1.currentTime =0;
}


function playMetronome(){
    playing = setTimeout(playMetronome, 500);   //speel elke halve seconde metronome af
    metronome.play();
}


function stopMetronome(){                       //stop timeout van de metronome
        clearTimeout(playing);
}

document.onkeydown = function(e) {              //speel de noot c1 als de a toets is ingedrukt
    if (e.which === 65){
        c1.play();
        c1.currentTime =0;
        document.getElementById("c1Button").classList.add("c1active");

    }   else if (e.which === 83){               //speel de noot d1 als de s toets is ingedrukt
        d1.play();
        d1.currentTime =0;
        document.getElementById("d1Button").classList.add("d1active");

    }   else if (e.which === 68){               //speel de noot e1 als de d toets is ingedrukt
        e1.play();
        e1.currentTime =0;
        document.getElementById("e1Button").classList.add("e1active");

    }   else if (e.which === 70){               //speel de noot f1 als de f toets is ingedrukt
        f1.play();
        f1.currentTime =0;
        document.getElementById("f1Button").classList.add("f1active");

    }   else if (e.which === 71){               //speel de noot g1 als de g toets is ingedrukt
        g1.play();
        g1.currentTime =0;
        document.getElementById("g1Button").classList.add("g1active");

    }   else if (e.which === 72){               //speel de noot a1 als de h toets is ingedrukt
        a1.play();
        a1.currentTime =0;
        document.getElementById("a1Button").classList.add("a1active");

    }   else if (e.which === 74){               //speel de noot b1 als de j toets is ingedrukt
        b1.play();
        b1.currentTime =0;
        document.getElementById("b1Button").classList.add("b1active");

    }
};


document.onkeyup = function(e){                 //verander css als een toets omhoog gaat
        document.getElementById("c1Button").classList.remove("c1active");
        document.getElementById("d1Button").classList.remove("d1active");
        document.getElementById("e1Button").classList.remove("e1active");   
        document.getElementById("f1Button").classList.remove("f1active");
        document.getElementById("g1Button").classList.remove("g1active");
        document.getElementById("a1Button").classList.remove("a1active");
        document.getElementById("b1Button").classList.remove("b1active");
};


document.getElementById("title").innerHTML = "Artiest van de dag: " + dagartiest(artiesten);
audiobutton1.addEventListener("click", playAudio, false);
audiobutton2.addEventListener("click", playAudio1, false);
audiobutton3.addEventListener("click", playAudio2, false);
audiobutton4.addEventListener("click", playAudio3, false);
audiobutton5.addEventListener("click", playAudio4, false);
audiobutton6.addEventListener("click", playAudio5, false);
audiobutton7.addEventListener("click", playAudio6, false);
metronomebutton.addEventListener("click", playMetronome);
stopmetronomebutton.addEventListener("click", stopMetronome);
document.addEventListener("load", dagartiest);

这是错误

Undeclared 'Audio'.
var c1 = new Audio("Piano/c1.mp3");
15.13Undeclared 'Audio'.
var d1 = new Audio("Piano/d1.mp3");
16.13Undeclared 'Audio'.
var e1 = new Audio("Piano/e1.mp3");
17.13Undeclared 'Audio'.
var f1 = new Audio("Piano/f1.mp3");
18.13Undeclared 'Audio'.
var g1 = new Audio("Piano/g1.mp3");
19.13Undeclared 'Audio'.
var a1 = new Audio("Piano/a1.mp3");
20.13Undeclared 'Audio'.
var b1 = new Audio("Piano/b1.mp3");
21.20Undeclared 'Audio'.
var metronome = new Audio("Piano/tick.wav");
27.0This function needs a "use strict" pragma.
function dagartiest(artiesten)  {               //kiest een random artiest uit de array
33.0Expected 'for' to be in a function.
for (i = 0; i < artiesten.length; i+=1) {       //Laat alle artiesten uit de array in de console zien
38.0This function needs a "use strict" pragma.
function playAudio() {                          //speel de noot c1
44.0This function needs a "use strict" pragma.
function playAudio1() {                         //speel de noot d1
50.0This function needs a "use strict" pragma.
function playAudio2() {                         //speel de noot e1
56.0This function needs a "use strict" pragma.
function playAudio3() {                         //speel de noot f1
62.0This function needs a "use strict" pragma.
function playAudio4() {                         //speel de noot g1
68.0This function needs a "use strict" pragma.
function playAudio5() {                         //speel de noot a1
74.0This function needs a "use strict" pragma.
function playAudio6() {                         //speel de noot b1
81.0This function needs a "use strict" pragma.
function playMetronome(){
87.0This function needs a "use strict" pragma.
function stopMetronome(){                       //stop timeout van de metronome
91.21This function needs a "use strict" pragma.
document.onkeydown = function(e) {              //speel de noot c1 als de a toets is ingedrukt
131.19This function needs a "use strict" pragma.
document.onkeyup = function(e){                 //verander css als een toets omhoog gaat

JSHint不会给我任何错误。

此外，如果有人可以帮助我弄清为什么它还在抱怨音频未声明，我将非常感谢您的帮助！

Answer 1

JSLint执行其作者Douglas Crockford认为适当的规则。其中之一是要求您以严格模式编写代码。 （我碰巧同意这是最佳做法。）

不幸的是，如果您告知"use strict";是针对浏览器的目标，那么JSLint也会抱怨，如果您将"use strict";放在文件的顶部（这很奇怪，因为这样做是完全合理的事情）。

所以您的选择是：

将"use strict";放在每个函数的顶部。
不要告诉您您正在定位浏览器，而是自己提供所有全局变量，并在文件顶部添加"use strict"; /*jslint browser: false, devel: true, white: true, long: true, for: true*/ /*global clearInterval, clearTimeout, document, event, FileReader, FormData, history, localStorage, location, name, navigator, screen, sessionStorage, setInterval, setTimeout, Storage, URL, window, XMLHttpRequest */ /*eslint-env browser*/ /*eslint 'no-console':0*/ var metronomebutton = document.querySelector("#playMetronome"); var stopmetronomebutton = document.querySelector("#stopMetronome"); // ...：
```
strict
```
使用其他内容，例如ESLint。（并且我注意到您在该代码中有几个面向ESLint的注释。）它提供了更好的文档和对规则的更多控制。例如，其与此1d 10:10 '2' 'A' 1d 10:10 '8' 'B' 1d 10:20 '6' 'A' 1d 10:20 '4' 'B' 1d 10:30 '2' 'A' 2d .....规则的等效记录在here中。

JSLint“此功能需要“严格使用”编译指示。”

1 个答案: