However, the benefits of TypeScript become more apparent as a project grows in size and complexity. Additionally, the untyped nature of JavaScript can make it feel faster to develop in, as developers can quickly iterate and experiment with different ideas. After all, JavaScript is a powerful and flexible language that can be used to create complex applications with relative ease. This object is like a blueprint or a recipe.At first glance, the benefits of using TypeScript may not be immediately apparent. Instead, it creates a JavaScript object that describes that piece of UI. When the above JSX code runs, it doesn't directly create something you can see on the screen. They can be used interchangeably.Ĭonsider below example: const element = Hello, world! JSX.Element and React.ReactElement are functionally the same type. Let's understand JSX.Element vs React.ReactElement vs React.ReactNode step by step: JSX.Element and React.ReactElement Props2: Props & React.ComponentPropsWithRef // to impersonate all the props of MyButtonForwardedRef and explicitly forwarding its ref Props: Props & React.ComponentPropsWithoutRef // to impersonate all the props of a button element and explicitly not forwarding its ref OnChange?: React.FormEventHandler // form events! the generic parameter is the type of event.target Style?: React.CSSProperties // to pass through style props alternative to `as any`: `as unknown as JSX.Element | null`Ĭhildren1: JSX.Element // bad, doesnt account for arraysĬhildren2: JSX.Element | JSX.Element // meh, doesn't accept stringsĬhildren3: React.ReactChildren // despite the name, not at all an appropriate type it is a utilityĬhildren4: React.ReactChild // better, accepts array childrenĬhildren: React.ReactNode // best, accepts everything (see edge case below)įunctionChildren: (name: string) => React.ReactNode // recommended function as a child render prop type In edge cases, you can add a type assertion or Fragments as workaround:Ĭonst M圜ompFragment: FunctionComponent = () => "Hello"Ĭonst M圜ompCast: FunctionComponent = () => "Hello" as any So using React.FC sparingly might be preferable. Interface ReactElement = string | JSXElementConstructor> type definition. What is the difference between JSX.Element, ReactNode and ReactElement?Ī ReactElement is an object with a type and props. How do I solve this with respect to null?.Why do the render methods of class components return ReactNode, but functional components return ReactElement?.What is the difference between JSX.Element, ReactNode and ReactElement?.To cut a long story short, I have three questions: However, if I do so, the compatibility issue is gone, but now TypeScript again complains about null not being a valid value. Again, after some searching I found, that for functional components you should use ReactElement instead. However, when creating a functional component, TypeScript complains about the ReactNode type. I searched the web and found that you should use ReactNode instead, which includes null and a few other things that can happen. returns null, since null is not a valid value for JSX.Element. I have always used JSX.Element as the return type, now this doesn't work any more if a component decides to not render anything, i.e. So far, this works pretty well, but I have a problem with the return types of my render functions, specifically in my functional components. I am currently migrating a React application to TypeScript.
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