In biology, cell theory is a scientific theory which describes the properties of cells. These cells are the basic unit of structure in all organisms and also the basic unit of reproduction.
The doctype declaration should be the very first thing in an HTML document, before the <html> tag. The doctype declaration is not an HTML tag; it is an instruction to the web browser about what version of the markup language the page is written in. The doctype declaration refers to a Document Type Definition (DTD).
Declaration Merging. Introduction. Some of the unique concepts in TypeScript describe the shape of JavaScript objects at the type level. One example that is especially unique to TypeScript is the concept of âdeclaration mergingâ. Understanding this concept will give you an advantage when working with existing JavaScript.