Category: JavaScript Answers

Sometimes, we want to replace all non alphanumeric characters, new lines, and multiple white space with one space with JavaScript.

In this article, we’ll look at how to replace all non alphanumeric characters, new lines, and multiple white space with one space with JavaScript.

How to replace all non alphanumeric characters, new lines, and multiple white space with one space with JavaScript?

To replace all non alphanumeric characters, new lines, and multiple white space with one space with JavaScript, we can use the string replace method with a regex.

For instance, we write

const s = text.replace(/[\W_]+/g, " ");

to call text.replace with a regex that matches all non-word characters and underscores with \W and _ respectively.

The g flag lets us match all instances of the characters.

And then we replace them all with spaces.

Conclusion

To replace all non alphanumeric characters, new lines, and multiple white space with one space with JavaScript, we can use the string replace method with a regex.

Sometimes, we want to add break statement in JavaScript array map method.

In this article, we’ll look at how to add break statement in JavaScript array map method.

How to add break statement in JavaScript array map method?

To add break statement in JavaScript array map method, we can use the array some method.

For instance, we write

const hasValueLessThanTen = myArray.some((val) => {
  return val < 10;
});

to call myArray.some with a callback that checks if any items in myArray has value less than 10.

Conclusion

To add break statement in JavaScript array map method, we can use the array some method.

Sometimes, we want to get local href value from anchor (a) tag with JavaScript.

In this article, we’ll look at how to get local href value from anchor (a) tag with JavaScript.

How to get local href value from anchor (a) tag with JavaScript?

To get local href value from anchor (a) tag with JavaScript, we can use the href property.

For instance, we write

const href = document.getElementById("aaa").href

to get the anchor element with ID 'aaa' with getElementById.

And then we get the href attribute value with href.

Conclusion

To get local href value from anchor (a) tag with JavaScript, we can use the href property.

Sometimes, we want to insert a row in an HTML table body in JavaScript.

In this article, we’ll look at how to insert a row in an HTML table body in JavaScript.

How to insert a row in an HTML table body in JavaScript?

To insert a row in an HTML table body in JavaScript, we can use the insertRow and insertCell methods.

For instance, we write

const tbodyRef = document
  .getElementById("myTable")
  .getElementsByTagName("tbody")[0];
const newRow = tbodyRef.insertRow();
const newCell = newRow.insertCell();
const newText = document.createTextNode("new row");
newCell.appendChild(newText);

to get the tbody element with

const tbodyRef = document
  .getElementById("myTable")
  .getElementsByTagName("tbody")[0];

Then we call insertRow to insert a tr element into the tbody element.

And then we call newRow.insertCell to insert a td element into the tr element.

Then we call createTextNode to create a text node.

Finally, we use

newCell.appendChild(newText);

to insert the text node into the td element.

Conclusion

To insert a row in an HTML table body in JavaScript, we can use the insertRow and insertCell methods.

Sometimes, we want to check if a background image is loaded with JavaScript.

In this article, we’ll look at how to check if a background image is loaded with JavaScript.

How to check if a background image is loaded with JavaScript?

To check if a background image is loaded with JavaScript, we can set the backgroundImage property.

For instance, we write

const src = "https://picsum.photos/200/300";
const image = new Image();
image.addEventListener("load", () => {
  body.style.backgroundImage = `url(${src})`;
});
image.src = src;

to create the img element with Image.

Then we listen for the load event on the image to check if it’s loaded.

If it is, then we set the backgroundImage to the URL of the loaded image.

Then we load the image by setting image.src to src.

Conclusion

To check if a background image is loaded with JavaScript, we can set the backgroundImage property.