Methods and properties chaining in JavaScript

Let us have an input:

html<input id="elem" value="text">

Let's display the input text:

javascriptlet elem = document.querySelector('#elem');
console.log(elem.value); // shows 'text'

As you can see, we first get an element by its id, write this element to the variable elem, and then display the property value from this variable

In fact, you can not enter the variable elem, but build a chain of dots in this way:

javascriptconsole.log( document.querySelector('#elem').value ); // shows 'text'

In the same way - in a chain - you can overwrite attributes:

javascriptdocument.querySelector('#elem').value = 'www';

html<img id="image" src="avatar.png">

javascriptlet image = document.querySelector('#image');
console.log(image.src);