Fast way to apply function to each value of an array?

Hi there,

I created a function Fx which takes in a single value as input, use it for some calculation and produces a single number as output.

I want to apply that function on every values of the array n.

n = 1:300000;

I tried using for loop but it takes too long. Thus, I'm looking for another way to speed it up other than For loop.

Thank you