我可以从同一对象中调用私有函数吗 javascript

can I call a private function from within the same object javascript

ETA:我不认为这个问题与链接的问题重复。我知道如何return一个私有变量(如下代码所示),这个问题是关于如何在同一个对象中调用私有函数。

我找不到具体 javascript 的相关信息。我声明了一个对象,在该对象中我声明了四个函数(三个是对象方法,一个不是)。我想使第四个成为对象方法,以便我可以从 jquery 中单独调用它(timer.displayTime(); ) 但是当我这样做时,startIntervalTimer 函数的使用停止工作。我正在尝试做的事情是否可行?

var startStopTime = function() {

 //This function is currently called inside startIntervalTimer(); 
 function displayTime() {
    //Display correct time
  };

//I WANT SOMETHING LIKE THIS INSTEAD BUT (SEE startIntervalTimer)
this.displayTime = function() {
//Display correct time
}

  var intervalTimer; 
  this.startIntervalTimer = function() {
    console.log(timeSetMS);
    intervalTimer = setInterval(function() {
      if(timeSetMS > 0) {
       timeSetMS -= 1000;
      displayTime(); //THIS IS WHERE AND HOW IT IS CALLED
      this.displayTime(); //THIS IS WHAT I'M GOING FOR, BUT IT WON'T WORK
      console.log(timeSetMS); 
      } else if(timeSetMS <= 0) {
        clearInterval(intervalTimer);
        console.log("timer stopped");
      }  
    }, 1000
    );
  }   
};

然后在 jquery 我有:

var timer = new startStopTime();
$("#timer-container,  #timer-label").click(function() {
    if(power == "off") {
      power = "on"; 
      timer.startIntervalTimer();
    } else if (power == "on") {
      power = "off";
      timer.stopTimer();
    }
   });

//I want to add this, below

$("#session-length").click(function() {
    //Change the display
    timer.displayTime();
    displayTime(); // This won't work obviously because it's out of scope
  });

您可以在对象内部声明另一个变量,即。 self:

var startStopTime = function() {
  //declare self
  var self = this;

  this.displayTime = function() {
  //Display correct time
  }

  var intervalTimer; 
  this.startIntervalTimer = function() {
    console.log(timeSetMS);
    intervalTimer = setInterval(function() {
      if(timeSetMS > 0) {
       timeSetMS -= 1000;
      displayTime(); 
      self.displayTime(); // use self instead
      console.log(timeSetMS); 
      } else if(timeSetMS <= 0) {
        clearInterval(intervalTimer);
        console.log("timer stopped");
      }  
    }, 1000
    );
  }   
};