Implementation of the Fibonacci sequence using the dynamic programming concepts memozation & tabulation

fibonacci.js

function fibMemo(n, memo) {

    if (memo[n]) return memo[n];
    if (n <= 1) return 1; 

    return memo[n] = fibMemo(n - 1, memo) + fibMemo(n - 2, memo);
}

function fibTab(n) {
    
    const tab = new Array(n);
    tab[0] = 1;
    tab[1] = 1;
    
    for (let i = 2; i <= n; i++) {
        tab[i] = tab[i - 1] + tab[i - 2];
    }
    
    return tab[n];
}