Question

Please explain what this code is doing step by step and how to get the answer of a= 6 , b = 11

const inc = x => x+1;
const dub = x => x+x;

const U =2;
const V =5;
const LR = (x,f) => f(x);
const RL = (f,x) => f(x);
const a = RL(dub, LR(U, inc));
const b = LR(RL(dub,V), inc);

a = 6

b= 11

Answer 1

Each step is numbered and commented for better understanding.

1. const inc = x => x+1; //inc is a function that inputs x and outputs x+1
2. const dub = x => x+x;. //dub is a function which inputs x and outputs the double value of x

3. const U =2; . // A const variable U with value assigned 2
4. const V =5; . //A constant variable V with value assigned 5
5. const LR = (x,f) => f(x); . //Function with X and a function as inputs and outputs the function with input as x
6. const RL = (f,x) => f(x);. //Function which will output according to the input X and the input function
7. const a = RL(dub, LR(U, inc)); //the step by step procedure can be implemented for this step as, RL(dub,LR(2,inc)) which results in RL(dub,3) which returns a=6.
8. const b = LR(RL(dub,V), inc); // likewise above, LR(10,inc) will yield b=11