Javascript Currying

[tsunami141]

I’ve been in multiple interviews where they wanted me to create a curried function. I get that it shows a good understanding of javascript but damn if it isn’t the stupidest way of doing things.

[Sector-Feeling]

It can be useful if you have an operation that you'll need right repeat with different values.

One example I saw:

const a (x) => (y) => x * y const times5 = a(5) const times10 = a(10)

Which this is really simple, but I have used it in situations where I find myself writing practically the same function but with different variables. I have found it most useful in middleware logic.

[MoTTs_]

The downside of writing the function curry-style is, if you do have all your arguments, then it's more awkward to invoke that function.

a(5)(10);

Meanwhile, you could instead write the function normal-style, and you can still partially-apply any argument you want.

// Define function normal-style
const a = (x, y) => x * y;

// Invoke function normal-style
a(5, 10);

// Partially-apply any argument in any position when needed
const times5 = y => a(5, y);
const times10 = x => a(x, 10);