How Do I Get The Decimal Places Of A Floating Point Number In Javascript

Understanding how to manipulate floating-point numbers in JavaScript is crucial for various programming tasks. One common operation you may encounter is extracting the decimal places from a floating-point number. In this guide, we will walk you through how to achieve this with JavaScript.

Using Math.floor and Modulo Operator

One approach to obtaining the decimal places of a floating-point number involves utilizing the `Math.floor` function and the modulo operator (%). The `Math.floor` method will round down the number to the nearest integer, and by subtracting this integer from the original number, we get the decimal part. Here is a simple code snippet demonstrating this technique:

function getDecimalPlaces(number) {
  return number - Math.floor(number);
}

const floatingNumber = 3.14159;
const decimalPlaces = getDecimalPlaces(floatingNumber);
console.log(decimalPlaces); // Output: 0.14159

In this code snippet, the `getDecimalPlaces` function takes a floating-point number as an argument, subtracts the truncated integer part (obtained by `Math.floor`) from the original number, and returns the decimal places.

Using Regular Expressions

Another method to extract decimal places involves leveraging regular expressions to manipulate the number as a string and extract the desired digits. Here's how you can accomplish this:

function getDecimalPlaces(number) {
  const decimalArray = number.toString().match(/.(d+)/);
  return decimalArray ? parseFloat(decimalArray[0]) : 0;
}

const floatingNumber = 6.28318;
const decimalPlaces = getDecimalPlaces(floatingNumber);
console.log(decimalPlaces); // Output: 0.28318

In this code snippet, the `getDecimalPlaces` function converts the floating-point number to a string and uses a regular expression to match the decimal part. If a match is found, it converts the matched string back to a floating-point number.

Conclusion

Being able to extract decimal places from a floating-point number is a useful skill in JavaScript programming. By employing techniques like using `Math.floor`, the modulo operator, or regular expressions, you can efficiently isolate the decimal portion of a floating-point number. With these strategies in your toolkit, you can enhance your coding capabilities and tackle a diverse range of numerical tasks with confidence.