Neglecting to utilize a parameter in a function

Question

Neglecting to utilize a parameter in a function

Here's a question from a beginner: what if I create a function named sendRequest that accepts multiple parameters for an ajax call?

I'm not really concerned about the ajax request itself, I just want to understand how the parameters work.

function sendRequest($el, url, trackingUrl, actionTypeString) {
 $.ajax({
   method: 'POST',
   url: url,
   actionTrackingUrl: trackingUrl,
   actionType: actionTypeString,
   el: $el,
 })
}

function testCase1() {
  // ......... code
  this.sendRequest($someEl, url, someTrackingUrl, someActionTypeString)
}

function testCase2() {
  // .......code
  this.sendRequest($someEl, someUrl, someActionTypeString);
}

In testCase2, how can I provide the 4th parameter (actionTypeString) without providing the 3rd parameter?

javascript ajax function

Answer 1

Answer №1

To execute testCase2, you must provide a null parameter as an argument.

  this.sendRequest($someEl, someUrl, null, someActionTypeString);

If you wish to include optional parameters, a common practice in JavaScript is to pass in an object containing all required parameters with meaningful names:

function sendRequest(options) {
 $.ajax({
   method: 'POST',
   url: options.url,
   actionTrackingUrl: options.trackingUrl,
   actionType: options.actionType,
   el: options.$el,
 })
}

function testCase1() {
  // ......... code
  this.sendRequest( {
         $el: $someEl,
         url: someUrl,
         trackingUrl: someTrackingUrl,
         actionType: someActionTypeString
  });
}

function testCase2() {
  // ......... code
  this.sendRequest( {
         $el: $someEl,
         url: someUrl,
         actionType: someActionTypeString
  });
}

Answer 2

To execute testCase2, you must provide a null parameter as an argument.

  this.sendRequest($someEl, someUrl, null, someActionTypeString);

If you wish to include optional parameters, a common practice in JavaScript is to pass in an object containing all required parameters with meaningful names:

function sendRequest(options) {
 $.ajax({
   method: 'POST',
   url: options.url,
   actionTrackingUrl: options.trackingUrl,
   actionType: options.actionType,
   el: options.$el,
 })
}

function testCase1() {
  // ......... code
  this.sendRequest( {
         $el: $someEl,
         url: someUrl,
         trackingUrl: someTrackingUrl,
         actionType: someActionTypeString
  });
}

function testCase2() {
  // ......... code
  this.sendRequest( {
         $el: $someEl,
         url: someUrl,
         actionType: someActionTypeString
  });
}

Answer 3

Answer №2

To assign parameters to named arguments, you must do so in a specific order. If you wish to pass the 4th argument without passing the 3rd, you will need to explicitly pass null.

function exampleFunction() {
  makeRequest($someElement, someURL, null, someAction);
}

Furthermore, it appears that there may be an error in your usage - in this context, 'this' refers to the global object. You should simply refer to the function name directly.

Answer 4

To assign parameters to named arguments, you must do so in a specific order. If you wish to pass the 4th argument without passing the 3rd, you will need to explicitly pass null.

function exampleFunction() {
  makeRequest($someElement, someURL, null, someAction);
}

Furthermore, it appears that there may be an error in your usage - in this context, 'this' refers to the global object. You should simply refer to the function name directly.

Neglecting to utilize a parameter in a function

Answer №1

Answer №2

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