javascript - 圆的面积

因此，我创建了一个.js文件来计算圆的面积，然后calculateArea（）需要对其进行计算。
它唯一要做的是提示符（）。我究竟做错了什么？

function calculateArea(myRadius){
  var area = (myRadius * myRadius * Math.PI);
  return area;

  function MyArea(){
    calculateArea(myRadius);
    alert("A circle with a " + myRadius +
          "centimeter radius has an area of " + area +
          "centimeters. <br>" + myRadius +
          "represents the number entered by the user <br>" + area +
          "represents circle area based on the user input.");
  }
}
var myRadius = parseFloat(prompt("Enter the radius of your circle in cm:",0));
calculateArea(myRadius);

最佳答案

您需要将功能MyArea保留在calculateArea之外，并从calculateArea内部调用MyArea。

调用MyArea函数而不是calculateArea。

示例片段：

function calculateArea(myRadius) {
  return (myRadius * myRadius * Math.PI);
}

function MyArea() {
  var area = calculateArea(myRadius);
  alert("A circle with a " + myRadius + "centimeter radius has an area of " + area + "centimeters. <br>" + myRadius + "represents the number entered by the user <br>" + area + "represents circle area based on the user input.");


}

var myRadius = parseFloat(prompt("Enter the radius of your circle in cm:", 0));
MyArea(myRadius);

PS：有更好的方法可以做到这一点。如有问题请发表评论。