這是我的代碼。https://www.jsfiddle.net/tpov743w/我正在嘗試完成多個圓形進度條。這個想法是讓它們動態(tài)工作，通過在需要時添加具有不同百分比值的額外 progressCircle_# 對象。如您所見，進度條加載數據并執(zhí)行動畫，但是當我檢查瀏覽器中的元素時，我注意到無數“ReferenceError: start is not defined”。我需要幫助來克服這個問題。感謝您的任何建議。var progressCircle_1 = {  procent: 89,  startFrom: 0,  incrementBy: 1,  canvasId: 'canvas',  procentId: 'procent',  funct: function() {    var start = setInterval(function() {      draw.call(progressCircle_1)    }, 50);  }}var progressCircle_2 = {  procent: 59,  startFrom: 0,  incrementBy: 1,  canvasId: 'canvas1',  procentId: 'procent1',  funct: function() {    var start = setInterval(function() {      draw.call(progressCircle_2)    }, 50);  }}progressCircle_1.funct();progressCircle_2.funct();function draw() {  (this.startFrom < this.procent) ? this.startFrom++: clearInterval(start);  var getCanvas = document.getElementById(this.canvasId).getContext('2d');  var getNumber = document.getElementById(this.procentId).innerHTML = this.incrementBy++;  getCanvas.beginPath();  getCanvas.arc(250, 250, 100, 0, 0.06283185307179587 * this.startFrom);  getCanvas.lineWidth = '15';  getCanvas.strokeStyle = "white";  getCanvas.lineCap = "round";  getCanvas.stroke();};