What are the return types of querySelector() and querySelectorAll()?

Answers:

• The querySelector() and querySelectorAll() methods in the DOM return different types of values:

  1. querySelector():

     • Return Type: It returns the first element within the document that matches the specified CSS selector(s). If no matching elements are found, it returns null.
     • Example:

       const element = document.querySelector('.my-class');
       // element will be the first element with the class 'my-class' or null if no such element exists.
       

  2. querySelectorAll():

     • Return Type: It returns a NodeList containing all the elements within the document that match the specified CSS selector(s). If no matching elements are found, it returns an empty NodeList.
     • Example:

       const elements = document.querySelectorAll('.my-class');
       // elements will be a NodeList of all elements with the class 'my-class', or an empty NodeList if none are found.
       

  In summary:

  • querySelector() returns a single element or null.
  • querySelectorAll() returns a NodeList, which can be empty but never null.

Related Questions:

• What is the difference between querySelector() and querySelectorAll()?

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• Can querySelectorAll() return an empty NodeList?

• Can querySelectorAll() select elements by class name?

• How do you use querySelectorAll() in JavaScript?

• How can you convert a NodeList from querySelectorAll() into an array?

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