JavaScript: Print an integer with commas as thousands separators

Last update on May 30 2022 09:58:50 (UTC/GMT +8 hours)

JavaScript validation with regular expression: Exercise-21 with Solution

Write a JavaScript function to print an integer with commas as thousands separators.

Pictorial Presentation:

JavaScript: Print an integer with commas as thousands separators

Sample Solution:-

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JavaScript function to print an integer with commas as thousands separators</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function thousands_separators(num)
  {
    var num_parts = num.toString().split(".");
    num_parts[0] = num_parts[0].replace(/\B(?=(\d{3})+(?!\d))/g, ",");
    return num_parts.join(".");
  }

console.log(thousands_separators(1000));
console.log(thousands_separators(10000.23));
console.log(thousands_separators(100000));

Sample Output:

1,000
10,000.23
100,000

Flowchart:

Live Demo:

See the Pen javascript-regexp-exercise-21 by w3resource (@w3resource) on CodePen.

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JavaScript: Tips of the Day

How to insert an item into an array at a specific index (JavaScript)?

What you want is the splice function on the native array object.

arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert). In this example we will create an array and add an element to it into index 2:

var arr = [];
arr[0] = "Jani";
arr[1] = "Hege";
arr[2] = "Stale";
arr[3] = "Kai Jim";
arr[4] = "Borge";

console.log(arr.join());
arr.splice(2, 0, "Lene");
console.log(arr.join());

Ref: https://bit.ly/2BXbp04