从百分比计算损失和利润

Question

当前比特币价格为 2700 美元。
价格在 7 天内上涨了 +34%。
我持有3.011 BTC，如何计算我的收益？

currentPrice = 2700;
percent = 34;
holdings = 3.011;
alert(  calcPec(currentPrice,percent,holdings)  );

当前比特币价格为 2700 美元。
价格在 2 天内上涨了 -7%。
我持有3.011 BTC，如何计算损失？

currentPrice = 2700;
percent = -7;
holdings = 3.011;
alert(  calcPec(currentPrice,percent,holdings)  );

// This is what i have but it is not correct
function calcPec(currentPrice,percent,holdings)
{
   res = currentPrice*percent/2;
   sum = holdings*res;
   return '$'+sum;
}

Answer 1

您忘记将百分比除以 100 得到一个分数。

// The current BTC price is 2700$.
// The price has increased by +34% in 7Days.
// I hold 3.011 BTC, how can i calculate my profit?

currentPrice = 2700;
percent = 34;
holdings = 3.011;
console.log(calcPec(currentPrice, percent, holdings));


// The current BTC price is 2700$.
// The price has increased by -7% in 2Days.
// I hold 3.011 BTC, how can i calculate my loss?

currentPrice = 2700;
percent = -7;
holdings = 3.011;
console.log(calcPec(currentPrice, percent, holdings));

function calcPec(currentPrice, percent, holdings) {
  const curr = holdings * currentPrice;
  const changed = curr * (1 + (percent / 100));
  return '$' + (changed - curr);
}

将来您可能希望将百分比定义为分数，以避免出现此类错误。所以而不是 percent = 34 你会做 percent = 0.34

编辑也修复了其他错误；

Answer 2

您可以将百分比值除以 100 得到变化的分数。

function calcPec(price, percent, holdings) {
    return '$' + (holdings * price * percent / 100).toFixed(2);
}

console.log(calcPec(2700, 34, 3.011));
console.log(calcPec(2700, -7, 3.011));

Answer 3

所以你持有 3.011 BTC，目前每个 BTC 2700 美元。 7 天前 BTC 的价格等于 100%，现在它已经上涨了 34%，所以 2700$ 等于 134%。要计算 7 天前的价格，您必须将 2700 除以 134%，即大约。 2014 美元。所以你的收入是 (2700 - 2014) * 3.011 = 2065

您的代码应如下所示：

function calcPec(currentPrice, percent, holdings)
{
    oldPrice = currentPrice / ((100 + percent) / 100);
    sum = (currentPrice - oldPrice) * holdings;
}

从百分比计算损失和利润

Calculate loss and profit from percentage

javascript

percentage