1. 状态模式

var offLightState = function(light){

      this.light = light;

}

• offLightState.prototype.buttonWasPressed = function(){

      console.log('弱光');

      this.light.setState(this.weakLightState);

}

var weakLightState = function(light){

      this.light = light;

}

weakLightState.prototype.buttonWasPressed = function(){

      console.log('弱光');

      this.light.setState(this.strongLightState);

}

var strongLightState = function(light){

      this.light = light;

}

strongLightState.prototype.buttonWasPressed = function(){

      console.log('弱光');

      this.light.setState(this.offLightState);

}

var light = function(){

      this.offLightState = new offLightState(this);

      this.weakLightState = new weakLightState(this);

      this.strongLightState = new strongLightState(this);

      this.button = null;

}

light.prototype.init = function(){

      this.currentState = this.offLightState;

      this.button.onclick = function(){

             this.currentState.buttonWasPressed();

      }

}

light.prototype.setState = function(state){

      this.currentState = state;

}

var light = new light();

light.init();