Category: JavaScript Answers

Sometimes, we want to remove all the children DOM elements in div with JavaScript.

In this article, we’ll look at how to remove all the children DOM elements in div with JavaScript.

How to remove all the children DOM elements in div with JavaScript?

To remove all the children DOM elements in div with JavaScript, we can use the removeChild method.

For instance, we write

while (node.hasChildNodes()) {
  node.removeChild(node.lastChild);
}

to use a while loop to check if the node has any child nodes left with hasChildNodes.

Then we call remove.removeChild to remove the node‘s lastChild in the loop body.

Conclusion

To remove all the children DOM elements in div with JavaScript, we can use the removeChild method.

Sometimes, we want to call .map() a JavaScript ES6 Map with JavaScript.

In this article, we’ll look at how to call .map() a JavaScript ES6 Map with JavaScript.

How to call .map() a JavaScript ES6 Map with JavaScript?

To call .map() a JavaScript ES6 Map with JavaScript, we convert it to an array, and then back to a map.

For instance, we write

const myMap = new Map([
  ["thing1", 1],
  ["thing2", 2],
  ["thing3", 3],
]);
const newEntries = Array.from(myMap, ([key, value]) => [key, value + 1]);
const newMap = new Map(newEntries);

to call Array.from with myMap and a callback to map the values to a new values for the map.

Then we create the map from the newEntries array.

Conclusiin

To call .map() a JavaScript ES6 Map with JavaScript, we convert it to an array, and then back to a map.

Sometimes, we want to prevent "The play() request was interrupted by a call to pause()" error with JavaScript.

In this article, we’ll look at how to prevent "The play() request was interrupted by a call to pause()" error with JavaScript.

How to prevent "The play() request was interrupted by a call to pause()" error with JavaScript?

To prevent "The play() request was interrupted by a call to pause()" error with JavaScript, we can check if the play is called only when the video is paused.

For instance, we write

let isPlaying = true;

video.onplaying = () => {
  isPlaying = true;
};

video.onpause = () => {
  isPlaying = false;
};

const playVid = () => {
  if (video.paused && !isPlaying) {
    return video.play();
  }
};

const pauseVid = () => {
  if (!video.paused && isPlaying) {
    video.pause();
  }
};

to set isPlaying to true when the video is playing.

And we set it to false when we pause the video.

We call video.play when the video is paused and isPlaying is false.

And we call video.pause when the video isn’t paused and isPlaying is true.

Conclusion

To prevent "The play() request was interrupted by a call to pause()" error with JavaScript, we can check if the play is called only when the video is paused.

Sometimes, we want to convert JavaScript iterable to array.

In this article, we’ll look at how to convert JavaScript iterable to array.

How to convert JavaScript iterable to array?

To convert JavaScript iterable to array, we can use the spread operator.

For instance, we write

const map = new Map([
  [1, "one"],
  [2, "two"],
]);

const newArr = [...map];

to convert the map to the newArr array.

newArr is an array with arrays of keys and values in the map.

Conclusion

To convert JavaScript iterable to array, we can use the spread operator.

Sometimes, we want to use JavaScript includes() in a case insensitive manner.

In this article, we’ll look at how to use JavaScript includes() in a case insensitive manner.

How to use JavaScript includes() in a case insensitive manner?

To use JavaScript includes() in a case insensitive manner, we can convert all strings to the same case.

For instance, we write

const arr = ["foo", "bar", "bar"];
const lookup = "bAr";
console.log(arr.some((x) => x.toLowerCase() === lookup.toLowerCase()));

to call arr.some with a callback that converts the lookup string and the arr entry string x to lower case with toLowerCase.

And then we compare them to see if they’re equal in the some callback.

some returns true if any value in arr matches the condition we return in the callback.

Conclusion

To use JavaScript includes() in a case insensitive manner, we can convert all strings to the same case.