A Visual Guide to Javascript for React developers - First-class functions
January 11, 2022
React is a Javascript library. There are certain concepts in Javascript that are more relevant to React development than others. This series of articles explores these concepts.
React relies on functions a lot. You may have heard that Javascript has first-class functions, but what does it mean?
A programming language is said to have First-class functions when functions in that language are treated like any other variable.
First-class function - MDN
In Javascript, we can 👇
Assign a function to a variable
Or store it in other data structures like objects and arrays.
Pass a function as an argument to another function
And then call it from the inside of this function
Return a function from another function
Note: A function that returns a function is called a Higher-Order Function.
First-class Function - MDN
Scope and Closures
These characteristics of Javascript functions allow for closures. Closures may be tricky, but understanding them gives you superpowers when working with React. We will explore closures in the coming chapters.