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JavaScript JavaScript and the DOM (Retiring) Traversing the DOM Getting the First and Last Child

Posted by Mike John
Mike John
3,182 Points

I would like to know what exactly is the difference between querySelector and querySelectorAll against .............????

I would like to know what exactly is the difference between querySelector and querySelectorAll against getElementsByClassName and getElementById and getElementsbyTagName..??? A detailed answer would be very much appreciated ..!

1 Answer

Steven Parker
Steven Parker
229,644 Points
Steven Parker
Steven Parker
229,644 Points

These all return either a single element or collection of elements, but get them different ways:

  • querySelector returns the first single element in the document that matches the CSS-type selector
  • querySelectorAll returns a collection of all elements in the document that match the selector
  • getElementsByClassName returns a collection of elements that have the specified class (not a selector)
  • getElementById*returns the single element in the document that has the specified ID (there can only be one)
  • getElementsbyTagName returns a collection of elements that have the specified tag name (type)

The methods using CSS-type selectors are newer and more versatile.

Click on any of the names to go to the MDN documentation page for full details on the function.