JSFiddle - React, Tailwind, and code Playground

JavaScript

function anyfunc(f){
	f()
}

class MyClass{
    constructor(){
        this.param1 = "";
        this.param2 = "";
    }
    setVar(){
        anyfunc(function(){
            this.param1 = "DSASDASD";
            //console,log(this.param1);
        });
    }
}

A = new MyClass();
A.setVar();
console.log(A.param1);