Category: JavaScript

Sometimes, we want to add line breaks to an HTML textarea with JavaScript.

In this article, we’ll look at how to add line breaks to an HTML textarea with JavaScript.

How to add line breaks to an HTML textarea with JavaScript?

To add line breaks to an HTML textarea with JavaScript, we can add '\r\n' to the string.

For instance, we write

const txtArea = document.getElementById("txt");
txtArea.value += text + "\r\n";

to select the text area with getElementById.

And then we append text + "\r\n" to the value property.

"\r\n" adds the line breaks.

Conclusion

To add line breaks to an HTML textarea with JavaScript, we can add '\r\n' to the string.

Sometimes, we want to get the difference between two arrays of objects in JavaScript.

In this article, we’ll look at how to get the difference between two arrays of objects in JavaScript.

How to get the difference between two arrays of objects in JavaScript?

To get the difference between two arrays of objects in JavaScript, we can use the array filter method.

For instance, we write

const arrayOne = [
  { value: "4a55eff3-1e0d-4a81-9105-3ddd7521d642", display: "alex" },
  { value: "644838b3-604d-4899-8b78-09e4799f586f", display: "james" },
  { value: "b6ee537a-375c-45bd-b9d4-4dd84a75041d", display: "jane" },
  { value: "e97339e1-939d-47ab-974c-1b68c9cfb536", display: "bob" },
  { value: "a63a6f77-c637-454e-abf2-dfb9b543af6c", display: "joe" },
];

const arrayTwo = [
  { value: "4a55eff3-1e0d-4a81-9105-3ddd7521d642", display: "alex" },
  { value: "644838b3-604d-4899-8b78-09e4799f586f", display: "james" },
  { value: "b6ee537a-375c-45bd-b9d4-4dd84a75041d", display: "jane" },
  { value: "e97339e1-939d-47ab-974c-1b68c9cfb536", display: "bob" },
];

const results = arrayOne.filter(
  ({ value: id1 }) => !arrayTwo.some(({ value: id2 }) => id2 === id1)
);

console.log(results);

to call arrayOne.filter with a callback that checks if any object with the id that’s the same as the item being looped through in arrayOne with arrayTwo.some.

Then we negate that to find the items in arrayOne that’s not in arrayTwo according to the value values.

Conclusion

To get the difference between two arrays of objects in JavaScript, we can use the array filter method.

Sometimes, we want to convert FormData (HTML5 object) to JSON with JavaScript.

In this article, we’ll look at how to convert FormData (HTML5 object) to JSON with JavaScript.

How to convert FormData (HTML5 object) to JSON with JavaScript?

To convert FormData (HTML5 object) to JSON with JavaScript, we can use the Object.entries method.

For instance, we write

const json = JSON.stringify(Object.fromEntries(formData));

to call Object.fromEntries with formData to convert the form data object to a plain object.

Then we call JSON.stringify to convert the plain object into a JSON string.

The plain object has the keys from the form data keys and the values from the form data values.

Conclusion

To convert FormData (HTML5 object) to JSON with JavaScript, we can use the Object.entries method.

Sometimes, we want to watch HTML input file selection event with JavaScript.

In this article, we’ll look at how to watch HTML input file selection event with JavaScript.

How to watch HTML input file selection event with JavaScript?

To watch HTML input file selection event with JavaScript, we can set the input’s onchange property to a function that runs when we select files.

For instance, we write

input.onchange = (e) => {
  //..
};

to set input.onchange to a function that runs when the file input’s file selection is changed.

Conclusion

To watch HTML input file selection event with JavaScript, we can set the input’s onchange property to a function that runs when we select files.