我正在尝试在 class 的帮助下打印已定义多边形的周长，但它给了我未定义为 output 请告诉我问题出在哪里

Question

I am getting undefined as output please tell me to resolve this and tell me where the problem is.

 class Polygon { constructor(side) { this.values = side; } perimeter() { var x; for (var i = 0; i > this.values.length; i++) { x = values[i]; x += values[i]; } return x; } } var triangle = new Polygon([3, 4, 5]); const rectangle = new Polygon([10, 20, 10, 20]); const square = new Polygon([10, 10, 10, 10]); const pentagon = new Polygon([10, 20, 30, 40, 43]); console.log(rectangle.perimeter()); console.log(square.perimeter()); console.log(pentagon.perimeter());

Answer 1

You have bugs in you code. Check this code and debug properly.

...
    perimeter(){ 
        var x = 0; // Initialize x to zero when begin
        for (var i = 0 ; i < this.values.length; i++){ // change greaeter than ( > ) symbol to less than symbol ( < )
            // x = values[i]; // remove this line
            x += this.values[i]; // put this keyword to infront
        }
        return x;
    }
}
...

Answer 2

You have to use this keyword while using the variable declared in the constructor and for adding values in x you have to assign 0 to x and i will be less than the length of the array else it will return just 0. Lastly you have to remove this line x = values[i] because it will reassign the value of x on each iteration of the loop.

class Polygon {
  constructor(side) {
    this.values = side;
  }
  perimeter() {
    var x = 0;
    for (var i = 0; i < this.values.length; i++) {
      x += this.values[i];
    }
    return x;
  }
}
var triangle = new Polygon([3, 4, 5]);

const rectangle = new Polygon([10, 20, 10, 20]);
const square = new Polygon([10, 10, 10, 10]);
const pentagon = new Polygon([10, 20, 30, 40, 43]);

console.log(rectangle.perimeter());
console.log(square.perimeter());
console.log(pentagon.perimeter());