Explanation of Codility answer

Javascript Course 2021
#1

I have done the below exercise from Codility: https://app.codility.com/programmers/lessons/2-arrays/cyclic_rotation/

Below are my answers:

function solution(A, K) {
    for (let i = 0; i = K; i++) {
            A.shift(A.pop());
        }
    return A;
}

Can anyone comment on my answer?

Also I don’t understnad the official answer as below.
What does " var newPos = (i+K) % A.length;" mean? What is “newPos” and “%” in this context?
I wonder if I should continue doing Codility exercises.

function solution(A, K) {
    // write your code in JavaScript (Node.js 4.0.0)
    
    var result = [];
    
    if(A.length === 1 || K === 0) {
        return A;
    }
    
    for(var i=0; i<A.length; i++) {
        var newPos = (i+K) % A.length;
        
        result[newPos] = A[i];
    }
    
    return result;
}