从原型函数访问原型值

Question

如何从open函数访问原型的removeConnection()数组？现在我在调用函数时得到ReferenceError: open is not defined。

function Connections() {}
Connections.prototype.open = [];

Object.defineProperty(Connections.prototype, 'total', {
  get: function total() {
    return this.open.length;
  }
});

Connections.prototype.removeConnection = function(res) {
  this.open = open.filter(function(storedRes) {
    if (storedRes !== res) {
      return storedRes;
    }
  });
}

var connections = new Connections();

Answer 1

对我而言，它会引发不同的错误Uncaught TypeError: open.filter is not a function，修复方法是将this.open = open.filter更改为this.open = this.open.filter。

参见runnable示例：

function Connections() {}
Connections.prototype.open = [];

Object.defineProperty(Connections.prototype, 'total', {
  get: function total() {
    return this.open.length;
  }
});

Connections.prototype.removeConnection = function(res) {
  this.open = this.open.filter(function(storedRes) {
    if (storedRes !== res) {
      return storedRes;
    }
  });
}

var connections = new Connections();

connections.open = ['one', 'two']
alert(connections.open)
connections.removeConnection('one')
alert(connections.open)

Answer 2

您错过了this。

Connections.prototype.removeConnection = function(res) {
  this.open = this.open.filter(function(storedRes) {
    if (storedRes !== res) {
      return storedRes;
    }
  });
}