javascript - 为什么我在这里收到 TypeError？

Question

为什么我收到类型错误无法在此处读取未定义的属性“0”？另外，我怎样才能完全控制我是通过引用还是通过值传递东西？我无法在任何地方找到如何做到这一点？必须有一些翻转我必须切换以允许这样做。必须记住默认情况下它是通过引用传递还是通过值传递，这真的很烦人。

function lineOfWines(wines) {
    let memo = new Array(wines.length)
    for (let i = 0; i < memo.length; i++) {
        memo[i] = new Array(wines.length).fill(null);
    }

    return lineOfWinesHelper(0, 0, wines, memo);
}

function lineOfWinesHelper(L, R, wines, memo) {

    if (L + R == wines.length) {
        return 0;
    }
    
    if (memo[L][R] !== null) {
        return memo[L][R];
    }

    

    sellLeft = (L + R + 1) * wines[L] + 
    lineOfWinesHelper(L + 1, R, wines, memo);

    sellRight = (L + R + 1) * wines[wines.length - 1 - R] + 
    lineOfWinesHelper(L, R + 1, wines, memo);

    memo[L][R] = Math.max(sellLeft, sellRight);

    return memo[L][R];
}

function main() {

    console.log(lineOfWines([1, 1]));
}

main();