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Discussion on: SvelteJS: The next big UI framework

 
tobiassn profile image
Tobias SN

According to Wikipedia, “reactive programming is a declarative programming paradigm concerned with data streams and the propagation of change.”. So basically if I say a = b + c, a will change when b or c change, and it doesn’t matter how it’s implemented.

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mstamstrom profile image
Marcus Stamström • Edited

Yes, that is true. But the article you are referring to also state that

"in reactive programming, the value of a is automatically updated whenever the values of b or c change, without the program having to re-execute the statement a:=b+c to determine the presently assigned value of a."

In react or VueJS, when a value like a in your example changes, we have to rerun the same code and thereby re-execute the statement a = b + c. Making React or VueJS not reactive by that definition. In SvelteJS, the values are automatically updated as in the definition.

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tobiassn profile image
Tobias SN

Not sure how Svelte would know what a is without rerunning that code.

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mstamstrom profile image
Marcus Stamström

In Svelte, we can reassign the value of a without redeclaring the inline function. Which we would have to do in React.

That is one of my points about Svelte being truly reactive.

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tobiassn profile image
Tobias SN

Not sure what you mean by “redeclaring the inline function”.