I learned it directly from html-> CSS-> JavaScript-> SQL-> PHP.

I haven’t learned C language, and I haven’t dabbled in any knowledge about data structures and algorithms.

Excuse me, if I want to learn algorithms now, what knowledge do I need?

Also, it seems that the current talk about data structures and algorithms are all described in C language. Do you have to learn C language before you can learn data structures and algorithms?

Does the algorithm require high mathematics knowledge?

High school math is enough without much math knowledge. Many people say that arithmetic requires mathematical knowledge. Maybe they have forgotten about high school mathematics.

When you plan to use algorithms to solve some mathematical problems, such as derivation of functions, integration and solution of linear equations, you need more mathematical knowledge, such as linear algebra, interpolation and approximation theory.