在函數javascript中訪問另一個函數的超時變量

Question

在javascript中，我正在做這樣的事情

first_function: function() {
              var timeout = setTimeout(function() {
              // doing something 
              }, 300000);
           },

在另一個函數中，在做了重要的事情后，我必須訪問timeout變量並清除超時。

 second_function : function () {
           // after opening the hardware, have to cleartimeout from first_function
            hardware.open().then(function() {
            clearTimeout(timeout);
            }
           // calling first_function only after hardware open
            this.first_function();

但是，我得到未定義的變量timeout ，我該如何解決這個問題呢？

在解決this.first_function()的promise之前，我無法調用this.first_function() then()

Answer 1

您可以將timeout變量存儲為另一個屬性，例如this.timeout ：

first_function: function() {
  this.timeout = setTimeout(function() {
    // doing something 
  }, 300000);
},


second_function: function() {
  // after opening the hardware, have to cleartimeout from first_function
  hardware.open().then(() => {
    clearTimeout(this.timeout);

    // calling first_function only after hardware open
    this.first_function();
  })
}

Answer 2

你可以把timeout放在另一個屬性中，比如你的函數或者你的函數之外。

var timeout;

first_function: function() {
  timeout = setTimeout(function() {
    // doing something 
  }, 300000);
},

second_function: function() {
  // after opening the hardware, have to cleartimeout from first_function
  hardware.open().then(() => {
    clearTimeout(timeout);
    // calling first_function only after hardware open
    this.first_function();
  })
}

Answer 3

我會這樣做;

var first_function  = _ => setTimeout(_ => doSomething, 300000),
    second_function = cto => hardware.open()
                                     .then(_ => clearTimeout(cto));

second_function(first_function());