使用 JavaScript 构建数组

Question

我正在尝试利用 网络音频 API。说明仅涵盖如何播放声音文件和操作其输出等。

我需要听一个人发出的嗡嗡声并找出声音频率，然后将其转换为音符。我需要构建一个包含从数码钢琴键盘演奏的单个音符生成的所有频率的数组。然后我将获取所有频率的模式以获得实际的音符。

我能够在 Console.log() 上显示我检测到的频率和音符，但是，我无法构建数组、获取模式，然后在播放新音符时清除数组。我的数组保持活动状态，因为代码处于事件侦听模式并保持活动状态以侦听下一个音符。

这是我的代码：

var arrayList = [];
function getModes(array) {

    var frequency = []; // array of frequency.
    var maxFreq = 0; // holds the max frequency.
    var modes = [];

    for (var i in array) {
        frequency[array[i]] = (frequency[array[i]] || 0) + 1; // increment frequency.

        if (frequency[array[i]] > maxFreq) { // is this frequency > max so far ?
            maxFreq = frequency[array[i]]; // update max.
        }
    }

    for (var k in frequency) {
        if (frequency[k] == maxFreq) {
            modes.push(k);
        }
    }

    return modes;
}


function updatePitch(time) {
    
    var cycles = new Array;
    analyser.getFloatTimeDomainData(buf);
    var ac = autoCorrelate(buf, audioContext.sampleRate);
    // TODO: Paint confidence meter on canvasElem here.

    if (DEBUGCANVAS) {  // This draws the current waveform, useful for debugging
        waveCanvas.clearRect(0, 0, 512, 256);
        waveCanvas.strokeStyle = "red";
        waveCanvas.beginPath();
        waveCanvas.moveTo(0, 0);
        waveCanvas.lineTo(0, 256);
        waveCanvas.moveTo(128, 0);
        waveCanvas.lineTo(128, 256);
        waveCanvas.moveTo(256, 0);
        waveCanvas.lineTo(256, 256);
        waveCanvas.moveTo(384, 0);
        waveCanvas.lineTo(384, 256);
        waveCanvas.moveTo(512, 0);
        waveCanvas.lineTo(512, 256);
        waveCanvas.stroke();
        waveCanvas.strokeStyle = "black";
        waveCanvas.beginPath();
        waveCanvas.moveTo(0, buf[0]);

        for (var i = 1; i < 512; i++) {
            waveCanvas.lineTo(i, 128 + (buf[i] * 128));
        }
        waveCanvas.stroke();
    }

    if (ac == -1) {
        detectorElem.className = "vague";
        pitchElem.innerText = "--";
        noteElem.innerText = "-";
        detuneElem.className = "";
        detuneAmount.innerText = "--";
    } else {
        detectorElem.className = "confident";
        pitch = ac;
        pitchElem.innerText = Math.round(pitch);
        var note = noteFromPitch(pitch);


        // Here is where I am converting the frequency to a note letter
        var noteString = noteStrings[note % 12];
        console.log(noteString);

        // This is where I am building the array range with the notes that I find
        // I have a nice array, but it keeps building and I do not know how to clear it for 
        // the next session.

        if (note >=36 && note <= 96) {      
            if (arrayList) {
                arrayList.push(noteString);
            }
            console.log(noteString);
        }
        else {
            console.log("not note");
            var MyNote = getModes(arrayList)
            noteElem.innerHTML = MyNote;
            arrayList = [];
            
        }

        //  This function remains active and continues to listen for the next not to 
        //  generate and new note letter
        
        var detune = centsOffFromPitch(pitch, note);
        if (detune == 0) {
            detuneElem.className = "";
            detuneAmount.innerHTML = "--";
        } else {
            if (detune < 0)
                detuneElem.className = "flat";
            else
                detuneElem.className = "sharp";
            detuneAmount.innerHTML = Math.abs(detune);
        }
    }
    
    if (!window.requestAnimationFrame)
        window.requestAnimationFrame = window.webkitRequestAnimationFrame;
    rafID = window.requestAnimationFrame(updatePitch);
}

当我演奏新音符时，如何清除数组并使用新数组？ 谢谢你的支持...