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JavaScript DOM Scripting By Example Adding and Removing Names RSVP Checkbox

Could someone explain chaining methods in javascript?

I don't quite understand chaining different methods in javascript, and where I can find a reference to different methods.

also, Im not sure if its properties of the selected element or methods.

for example:

const paragraph = document.querySelector(".paragraph");

paragraph.style.color = "red"; // chaining style and color

However, I had trouble understanding the checked method

const checkbox = document.querySelector(".checkbox");
const checked = checkbox.checked // chaining checked method

if(checked == true) {
   // do something
} else {
  // do something else
}

From what I gather, the checked variable holds a boolean of either true or false.

but I don't understand whats going on

1 Answer

Steven Parker
Steven Parker
229,771 Points

This is not the same thing as "chaining methods".

Generally "chaining methods" refers to when you call methods on the result of other methods. It does look slightly similar in that it also uses dots, but the method calls will have parentheses, possibly with arguments in them.

Here, you are just using the dot notation for selecting an object property. For example, "checked" is a property of a checkbox object, and as you said will either be true or false to show if the box has a mark in it. And "style" is a property of a paragraph object, but it is itself also an object that has a "color" property.

Does that help?

Ok, great, I have a better idea now. Thanks, Steven