Category: JavaScript

Sometimes, we want to check if JavaScript object is JSON.

In this article, we’ll look at how to check if JavaScript object is JSON.

How to check if JavaScript object is JSON?

To check if JavaScript object is JSON, we can use the JSON.parse method.

For instance, we write

const isJson = (data) => {
  try {
    const testIfJson = JSON.parse(data);
    if (typeof testIfJson === "object") {
      return true;
    } else {
      return false;
    }
  } catch {
    return false;
  }
};

to call JSON.parse with data to parse the data string.

If its type is 'object', then it’s JSON is it’s not null.

Otherwise, it’s not JSON.

If JSON.parse can’t parse data, an error will be thrown and false is returned since it’s not JSON.

Conclusion

To check if JavaScript object is JSON, we can use the JSON.parse method.

Sometimes, we want to debug FormData.append("key", "value") is not working with JavaScript.

In this article, we’ll look at how to debug FormData.append("key", "value") is not working with JavaScript.

How to debug FormData.append("key", "value") is not working with JavaScript?

To debug FormData.append("key", "value") is not working with JavaScript, we can loop through the values with a loop.

For instance, we write

for (const data of formData) {
  console.log(data);
}

to loop through the entries of the formData FormData object with a for-of loop.

In it, we log the data value.

This works because a FormData object is an iterable object.

Conclusion

To debug FormData.append("key", "value") is not working with JavaScript, we can loop through the values with a loop.

Sometimes, we want to check if a value is not null and not empty string in JavaScript.

In this article, we’ll look at how to check if a value is not null and not empty string in JavaScript.

How to check if a value is not null and not empty string in JavaScript?

To check if a value is not null and not empty string in JavaScript, we can use the !== operator.

For instance, we write

if (data !== null && data !== "") {
  // ...
}

to check if data isn’t null and data isn’t an empty string with

data !== null && data !== ""

Conclusion

To check if a value is not null and not empty string in JavaScript, we can use the !== operator.

Sometimes, we want to iterate over a JavaScript associative array in sorted order.

In this article, we’ll look at how to iterate over a JavaScript associative array in sorted order.

How to iterate over a JavaScript associative array in sorted order?

To iterate over a JavaScript associative array in sorted order, we can get the keys of the object with Object.keys as an array.

Then we call the sort method on the array.

For instance, we write

const sortedKeys = Object.keys(a).sort();

to get the keys of object a as an array with Object.keys.

Then we call sort to return an array that sort the array of keys alphabetically.

Conclusion

To iterate over a JavaScript associative array in sorted order, we can get the keys of the object with Object.keys as an array.

Sometimes, we want to simulate a click by using x, y coordinates in JavaScript.

In this article, we’ll look at how to simulate a click by using x, y coordinates in JavaScript.

How to simulate a click by using x, y coordinates in JavaScript?

To simulate a click by using x, y coordinates in JavaScript, we can call the initMouseEvent method.

For instance, we write

const click = (x, y) => {
  const ev = document.createEvent("MouseEvent");
  const el = document.elementFromPoint(x, y);
  ev.initMouseEvent(
    "click",
    true /* bubble */,
    true /* cancelable */,
    window,
    null,
    x,
    y,
    0,
    0 /* coordinates */,
    false,
    false,
    false,
    false /* modifier keys */,
    0 /*left*/,
    null
  );
  el.dispatchEvent(ev);
};

to create the mouse event object by calling the createElement method with 'MouseEvent'.

Then we call elementFromPoint to get the element that we want to click on with the x and y coordinates of the screen.

Next we call initMouseEvent with a few arguments to initialize the mouse event.

'click' triggers a click.

Then we call it with other arguments to set some options described in the comments.

Finally, we call dispatchEvent to trigger the mouse event.

Conclusion

To simulate a click by using x, y coordinates in JavaScript, we can call the initMouseEvent method.