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In React terms, "functional" almost always implies the opposite of purely functional. It just means that the component is declared by a function instead of a cl
by wiredearp 4y ago
In React terms, "functional" almost always implies the opposite of purely functional. It just means that the component is declared by a function instead of a class. First time you call it, the function can assign state that it may reference in future calls, not unlike the methods of a class. How they actually go about this is however almost entirely weird.
- bigDinosaur 4y agoClasses in JS are just functions anyway, and functions can have state. Saving the state of a function is a different thing, but of course JS allows that, too. Why is it weird?
- wiredearp 4y agoClass instances are objects and it's the objects that have state. Functions can only abuse themselves as objects to store state. function johnson() { johnson.state = {}; } This is however shared state and the state will be reset whenever the function is called a second time. So what you normally do with a function is to pass the state via arguments and now the same function can work with different states. React could totally do this via props or as a second argument. function Johnson(props, state) {} Instead they changed the laws of functions so that a function can act different the first time it is called and also be called the first time multiple times if and when the function calls a functions that looks like JavaScript but follow different rules [1]. This is weird. [1] https://reactjs.org/docs/hooks-rules.html#only-call-hooks-at-the-top-level https://reactjs.org/docs/hooks-rules.html#only-call-hooks-at...
- bigDinosaur 4y agoAs far as I know, hooks use closures to store state, and that's neither abuse nor weird. Am I missing something?