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Appendix - Technical References

How to write a REGEX?​

A regular expression (REGEX) is a search pattern for strings.

  • [] : A character among a list (e.g. [a-z] a lowercase letter).
  • () : A capture group.
  • + : The previous character, one or more times.
  • : The previous character, zero or more times.
  • ? : The previous character is optional (zero or one time).
  • . : Any character.
  • ^ : Start of the string.
  • $ : End of the string.
  • \\ : Escape character (e.g. \\. for a literal dot).
  • | : Logical OR (e.g. http|https).

How to find an element with a CSS selector?​

CSS selectors target elements in an HTML page.

  • #id : Targets an element by its identifier (e.g. #main-content).
  • .class : Targets elements by their class (e.g. .product-title).
  • element : Targets all tags of this type (e.g. h1).
  • element.class : Targets element tags that have the class class.
  • parent descendant : Targets a descendant inside a parent (e.g. div .button).
  • parent > child : Targets a child that is a direct child of parent.
  • :nth-child(n) : Targets the n-th child of its parent.

The components of a URL​

For the URL https://ecommerce.seenaptic.com/fr/recherche?s=webcam#results:

  • protocol: https:
  • hostname: ecommerce.seenaptic.com
  • pathname: /fr/recherche
  • search (query string): ?s=webcam
  • hash: #results
  • origin: https://ecommerce.seenaptic.com
  • href: The complete URL.