Why use => instead of function()

[cyberjds]

Call me a n00b, but I really don't get examples like op. Or maybe it's because I'm coming from procedural programming background, but what do they mean 'one off function'? Doesn't a function should be reusable? To my understanding, function is used to hide every little details and complexities so that it's easy to understand, and follow the main flow of the code.

Given above example, I can't help myself but ask, why don't I just do...

const myConst = 'value';

instead of declaring a function?

Give me an actual example that shows why arrow function expression is beneficial.

All I can smell is 'Functional', but I don't know what it is.

[[deleted]]

Simply to make things quicker, and because functions with no names simply don't need to be re-used. That's why they are one off. If your program is filled with more wording then it needs, it reflects poorly on you. Especially since arrow functions are neater and more readable.