在循环语句中向图形遍历对象添加多个属性方法

// 定义图形遍历对象
var shapes = [
  { type: 'circle', radius: 5 },
  { type: 'rectangle', width: 10, height: 20 },
  { type: 'triangle', base: 8, height: 12 }
];

// 遍历图形集合并添加属性方法
for (var i = 0; i < shapes.length; i++) {
  var shape = shapes[i];

  // 添加属性
  shape.color = 'red';

  // 添加方法
  shape.calculateArea = function() {
    if (this.type === 'circle') {
      return Math.PI * this.radius * this.radius;
    } else if (this.type === 'rectangle') {
      return this.width * this.height;
    } else if (this.type === 'triangle') {
      return 0.5 * this.base * this.height;
    }
  };
}

// 打印每个图形的颜色和面积
for (var i = 0; i < shapes.length; i++) {
  var shape = shapes[i];
  console.log('Shape color:', shape.color);
  console.log('Shape area:', shape.calculateArea());
}