Question

首先，我是学习编码的新手。在我的代码中，我想创建一个函数“Square”，它通过使用你传入的length参数创建一个方形对象。另一个函数来计算它的周长。这是我的代码，我找不到我的错，你能不能帮助我？

function Square(length){
    this.length = length;
}

var calcPerimeter = function() {
  return this.sideLength * 4;
};
var calcArea = function() {
    return this.sideLength * this.sideLength ;
};

var p = square.calcPerimeter();
var a = square.calcArea();

var calcPerimeter2 = function(n){
    return n*4;
 };
var square1 = new Square(5);
square1.calcPerimeter2();

Answer 1

也许这就是你要找的东西：

function Square(length){
    this.sideLength = length;
}

Square.prototype.calcPerimeter = function() {
  return this.sideLength * 4;
};
Square.prototype.calcArea = function() {
    return this.sideLength * this.sideLength ;
};

var square = new Square(5);

console.log(square.calcPerimeter());
console.log(square.calcArea());

Answer 2

试试这个......

    function Square(length){
     this.length = length; //Constructor
    }

    Square.prototype.calcPerimeter = function(){
      return this.length * 4;
    }

    Square.prototype.calcArea = function() {
      return this.length * this.length;
    }

   var s = new Square(5);
   s.calcPerimeter();

使用此模式，您可以在javascript中模拟继承，此模式称为＆＃34; Prototype＆＃34;。希望这对你有用.... 此致

Answer 3

我不知道你在这段代码中做了什么，但我会像这样做代码：

function Square(length){
    this.length = length;

    this.calcSideLength = function() {
        this.sideLength = /* Your code to calculate sideLength */;
    };

    this.calcPerimeter = function() {
        return this.sideLength;
    };

    this.calcArea = function() {
        return this.sideLength * this.sideLength;
    };

    this.calcPerimeter2 = function(n) {
        return n*4;
    };
}

var square = new Square(5);

var p = square.calcPerimeter();
var a = square.calcArea();

var square1 = new Square(5);
square1.calcPerimeter2(/* send a number */);

我无法运行我的方法-JavaScript

3 个答案: