On the question of function, I am not good at math in primary school. I can only calculate addition, subtraction, multiplication and division. Where should I start to learn about programming functions now? Don't worry, your poor math in primary school and your poor math function in junior high school or university will not be just obstacles to learning new things.

The scores of those mathematical functions are for specific function formulas, and the programming functions you learn are not necessarily related to them. To learn programming functions, you only need to understand the connotation of functions anyway. These functions represent: some things, after some changes, produce other things; Mathematically, given an x, through the formula, until a result; In the program, given some parameters, some parameters are generated by changing the process. The description here may not be very appropriate if the main idea is this. This is another question I answered:

About how to learn functions well.

Just know what the input parameters are and what the output parameters are, and then know what the function process has done to the input parameters and given the output parameters. This is a way to write or understand functional code for yourself. If you use a function, you just need to know what parameters the function needs and what parameters it can output.

I think this method can also be used to learn mathematical functions. Study hard. When you get to know and understand it, you will find that it is not as difficult as you thought at first. Good luck!