Category: JavaScript

Sometimes, we want to detect rotation of Android phone in the browser with JavaScript.

In this article, we’ll look at how to detect rotation of Android phone in the browser with JavaScript.

How to detect rotation of Android phone in the browser with JavaScript?

To detect rotation of Android phone in the browser with JavaScript, we can listen for the orientationchange event.

For instance, we write

const supportsOrientationChange = "onorientationchange" in window;
constorientationEvent = supportsOrientationChange
  ? "orientationchange"
  : "resize";

window.addEventListener(
  orientationEvent,
  () => {
    console.log(window.orientation, screen.width);
  },
  false
);

to get the event name by checking "onorientationchange" in window.

If onorientationchange is available that means we can listen for the orientationchange event.

Otherwise, we listen for the resize event.

Then we call addEventListener to listen to either event and get the orientation and screen’s width with screen.width.

Conclusion

To detect rotation of Android phone in the browser with JavaScript, we can listen for the orientationchange event.

Sometimes, we want to get difference in months between two dates in JavaScript.

In this article, we’ll look at how to get difference in months between two dates in JavaScript.

How to get difference in months between two dates in JavaScript?

To get difference in months between two dates in JavaScript, we subtract the months from the 2 dates.

Then we add back the number of years difference converted to months.

For instance, we write

const monthDiff = (dateFrom, dateTo) => {
  return (
    dateTo.getMonth() -
    dateFrom.getMonth() +
    12 * (dateTo.getFullYear() - dateFrom.getFullYear())
  );
};

to get the monthDiff function.

In it, we call getMonth to get the months.

We get the difference with

dateTo.getMonth() - dateFrom.getMonth()

And we add the years difference with

12 * (dateTo.getFullYear() - dateFrom.getFullYear()

Conclusion

To get difference in months between two dates in JavaScript, we subtract the months from the 2 dates.

Then we add back the number of years difference converted to months.

Sometimes, we want to find and remove objects in an array based on a key value in JavaScript.

In this article, we’ll look at how to find and remove objects in an array based on a key value in JavaScript.

How to find and remove objects in an array based on a key value in JavaScript?

To find and remove objects in an array based on a key value in JavaScript, we can use the filter method.

For instance, we write

const newArray = myArray.filter((obj) => {
  return obj.id !== id;
});

to call myArray.filter with a callback to return all the items with obj.id not equal to id.

obj is the object is being processed in myArray.

Conclusion

To find and remove objects in an array based on a key value in JavaScript, we can use the filter method.

Sometimes, we want to parse date without time zone with JavaScript.

In this article, we’ll look at how to parse date without time zone with JavaScript.

How to parse date without time zone with JavaScript?

To parse date without time zone with JavaScript, we can add the time zone offset to the date without time zone.

For instance, we write

const date = new Date("2022-08-25T00:00:00");
const userTimezoneOffset = date.getTimezoneOffset() * 60000;
const d = new Date(date.getTime() - userTimezoneOffset);

to create a date object in UTC.

Then we call date.getTimezoneOffset to get the time zone offset in hours.

Then we multiply that by 60000 to get the offset in milliseconds.

Next, we call getTime to get the timestamp of date in milliseconds and then subtract that by userTimezoneOffset to get the date d that is in the local time zone.

Conclusion

To parse date without time zone with JavaScript, we can add the time zone offset to the date without time zone.

Sometimes, we want to reset setTimeout with JavaScript.

In this article, we’ll look at how to reset setTimeout with JavaScript.

How to reset setTimeout with JavaScript?

To reset setTimeout with JavaScript, we can call the clearTimeout function.

For instance, we write

const myTimer = setTimeout(() => {
  //...
}, 115000);

//...

clearTimeout(myTimer);

to call setTimeout to return a timer ID number and run the function after 115000 milliseconds.

Then we call clearTimeout with myTimer to stop the timer.

Conclusion

To reset setTimeout with JavaScript, we can call the clearTimeout function.