How I'm learning the basics of Dynamic Programming!

let fib = (n) => {    if (n <= 2) return 1;    return fib(n - 1) + fib(n- 2);};

1. fib(3)     * call function with integer 3 as an input2. function declares n = 33. evaluate (n <= 2)    * n is currently 3, which is not less than, or equal to 34. evaluate (n - 1)    * n is 3, subtract 1 and n == 25. declare n = 2    * now n has been reduced to 2 by previous evaluation 6. evaluate (n <= 2)    * n = 2, n is less than, or equal to 27. call fib(n - 1)     * n - 1 = 1    n is now less than or equal to 2, this is base case    now the recursive function will start to evaluate the -2 side of the return statement, at this point it will evaluate n at the value of 3 again.8. evaluate (n - 2)    * 3 - 2 = 1    this is a base case9. declare n = 1    * function now receives 1 as input10. evaluate (n <= 2)     * 1 is less than or equal to 211. call fib(n - 2) = 1    * base case, no further work to be done12. return 1 + 1 (return fib(n-1) + fib(n - 1))    * the value that was left from evaluating the -1 side of the tree was 1, from step 7. The Value from evaluating the -2 side was also 1, from step 11. 1 + 1 = 2. 

           fib(3)  declaration (n = 3)                                                   /      \         -1  /        \   -2                                                  /          \                                               (2)         (1) base                                            /                      /                                      (1) base   

            fib(4)  declaration (n = 4)                                                   /      \         -1   /        \   -2             /          \            (3)         (1)            / \                                            /   \                                             /     \                                        (2)     (1)                                                                   |         |        (1)// 1+1+1 = 3