在 Javascript 中为数字添加逗号

Posted 2023-04-14

【中文标题】在 Javascript 中为数字添加逗号

【英文标题】：Add commas to numbers in Javascript

【发布时间】：2018-04-15 18:28:23

【问题描述】：

我正在为我的班级编写一个程序，我们还没有真正了解如何用逗号格式化数字，我做了一些研究并尝试使用 toLocalestring()，但无法让它工作。我不确定我是否没有把它放在正确的位置，或者是否有另一种方法可以将逗号放在我想要的位置。我将发布我的代码，看看是否有人知道我需要做什么。我只需要逗号显示在余额和已付利息列中。另外，此时我必须根据课程要求使用 console.log() 。

function displayWelcome() 
  console.log("Welcome!");
  console.log("This program will determine the time to pay off a credit card and the interest paid based on the current balance, the interest rate, and the monthly payments made.");


function calculateminimumPaymentment(balance, minimumPaymentRate) 
  return Math.max(20, balance * minimumPaymentRate);


function displayPayments(balance, interest, minimumPayment) 

  var pad = 17;
  console.log("Balance on your credit card: $" + balance.toFixed(2));
  console.log("Interest Rate: " + (interest * 100) + "%");
  console.log("Assuming a minimum payment of 2% of the balance ($20 min)");
  console.log("Your minimum payment would be: $" + minimumPayment);
  console.log();
  console.log('Year'.padStart(pad), 'Balance'.padStart(pad - 10), 'Payment Number'.padStart(pad - 1), 'Interest Paid'.padStart(pad - 4), 'Minimum Payment'.padStart(pad - 3));
  var acum = 0;
  var yearcount = 0;
  var paynum = 0;
  var interestPaid = 1;
  var year = 0;


  while (balance > 0) 
    paynum++;
    interestPaid = balance * (interest / 12);
    balance = Math.max(0, balance - (minimumPayment - balance * interest / 12));
    minimumPayment = Math.max(20, balance * minimumPaymentRate);
    acum = (parseFloat(acum) + parseFloat(interestPaid)).toFixed(2);
    if (yearcount % 12 === 0) 
      year++;
      console.log(
        ('' + year).padStart(pad),
        '$' + parseFloat(balance).toFixed(2).padStart(pad - 9),
        ('' + paynum).padStart(pad - 3),
        '$' + parseFloat(interestPaid).toFixed(2).padStart(pad - 5),
        '$' + parseFloat(minimumPayment).toFixed(2).padStart(pad - 3)
      );
     else 
      console.log(
        ''.padStart(pad),
        '$' + parseFloat(balance).toFixed(2).padStart(pad - 9),
        ('' + paynum).padStart(pad - 3),
        '$' + parseFloat(interestPaid).toFixed(2).padStart(pad - 5),
        '$' + parseFloat(minimumPayment).toFixed(2).padStart(pad - 3)
      );
    
    yearcount++;
  


var balance = 1500;
var minimumPaymentRate = 0.02;
var interest = 0.18;

displayWelcome();
var minimumPayment = calculateminimumPaymentment(balance, minimumPaymentRate);

displayPayments(balance, interest, minimumPayment);

【问题讨论】：

在询问之前尝试搜索类似的问题。您的问题有很多问题和答案。见***.com/questions/149055/…

How can I format numbers as dollars currency string in javascript?的可能重复

愿这 (developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…) 对您有所帮助

【参考方案1】：

您必须自己格式化数字。先将其转为字符串，然后用正则表达式将点替换为逗号：

var a = 1234.5678;
var b = a.toFixed(2);
var c = b.replace(/\./, ',');

console.log(a, b, c);