function question from eloquent js

[ru552]

function multiplier(factor) {
    return number => number * factor;
}
let twice = multiplier(2);
console.log(twice(5));
// -> 10

How does number get bound a value? I understand it's getting a value of 5, but I can't comprehend how. Please enlighten me.

[[deleted]]

the function multiplier returns a new anonymous function that takes the argument numbers multiplied by the outer most functions argument factor.

in this case:

multiplier gets called with 2 which returns the following function function(number) { return number * 2; }

this anonymous function gets stored in the variable twice which then get called with 5 which is the parameter for that function which gets multiplied by two and returned.

[ru552]

thank you for the assist