Author: John Au-Yeung

Sometimes, we want to set element width or height in JavaScript.

In this article, we’ll look at how to set element width or height in JavaScript.

How to set element width or height in JavaScript?

To set element width or height in JavaScript, we set the style.width and style.height properties.

For instance, we write

e1.style.width = "400px";
e1.style.height = "200px";

to set the width of the el element to 400px and the height of el to 200px.

Conclusion

To set element width or height in JavaScript, we set the style.width and style.height properties.

Sometimes, we want to check if element has any children in JavaScript.

In this article, we’ll look at how to check if element has any children in JavaScript.

How to check if element has any children in JavaScript?

To check if element has any children in JavaScript, we can use various properties of the element.

For instance, we write

if (element.firstChild) {
  // ...
}

if (element.hasChildNodes()) {
  // ...
}

if (element.childNodes.length > 0) {
  // ...
}

to check if the firstChild is available with element.firstChild,.

If it’s set, then element has at least one child.

We can also call hasChildNodes to check if it has any child elements.

Or we can check if element.childNodes.length is bigger than 0 to do the same thing.

Conclusion

To check if element has any children in JavaScript, we can use various properties of the element.

Sometimes, we want to add the JavaScript equivalent of the Python pass statement that does nothing.

In this article, we’ll look at how to add the JavaScript equivalent of the Python pass statement that does nothing.

How to add the JavaScript equivalent of the Python pass statement that does nothing?

To add the JavaScript equivalent of the Python pass statement that does nothing, we can add an empty block.

For instance, we write

if (condition) {
}

to add an empty if block which does nothing.

Conclusion

To add the JavaScript equivalent of the Python pass statement that does nothing, we can add an empty block.

Sometimes, we want to extend error in JavaScript with ES6 syntax.

In this article, we’ll look at how to extend error in JavaScript with ES6 syntax.

How to extend error in JavaScript with ES6 syntax?

To extend error in JavaScript with ES6 syntax, we can use the extends keyword.

For instance, we write

class ExtendableError extends Error {
  constructor(message) {
    super();
    this.message = message;
    this.stack = new Error().stack;
    this.name = this.constructor.name;
  }
}

to create the ExtendableError class which inherits from the Error class.

In the constructor, we call super to initialize the parent constructor.

Then we add the instance properties for the constructor instance with the next 3 lines.

Conclusion

To extend error in JavaScript with ES6 syntax, we can use the extends keyword.

Sometimes, we want to get objects value if its name contains dots with JavaScript.

In this article, we’ll look at how to get objects value if its name contains dots with JavaScript.

How to get objects value if its name contains dots with JavaScript?

To get objects value if its name contains dots with JavaScript, we can use square brackets.

For instance, we write

const smth = myData.list[0]["points.bean.pointsBase"][0].time;

to put "points.bean.pointsBase" in square brackets to access this property in the myData object.

Conclusion

To get objects value if its name contains dots with JavaScript, we can use square brackets.