---
title: "Describe the parseInt and parseFloat functions and their use in converting strings to numbers."  
description: "Describe the parseInt and parseFloat functions and their use in converting strings to numbers."  
author: "Steilla Mitchel"  
published: 2023-10-30  
updated: 2023-10-31  
canonical: https://www.mindstick.com/forum/160330/describe-the-parseint-and-parsefloat-functions-and-their-use-in-converting-strings-to-numbers  
category: "javascript"  
tags: ["javascript", "datatype", "type conversion"]  
reading_time: 2 minutes  

---

# Describe the parseInt and parseFloat functions and their use in converting strings to numbers.

[Describe](https://www.mindstick.com/interview/12752/what-is-ddms-describe-some-of-its-capabilities) the parseInt and parseFloat [functions](https://www.mindstick.com/forum/160140/explain-the-role-of-functions-as-a-service-faas-in-serverless-computing) and their use in converting [strings](https://www.mindstick.com/forum/161912/explain-the-python-strings) to numbers.

## Replies

### Reply by Aryan Kumar

In JavaScript, **parseInt** and **parseFloat** are two built-in functions used for converting strings to numbers. They are particularly useful when you need to extract numeric values from user input or manipulate strings containing numeric data.

**parseInt Function**:

- **parseInt** is used to convert a string into an integer (whole number). It takes two arguments: the string you want to parse and an optional radix (base for the numeral system).
- It reads the string from left to right until it encounters a non-numeric character and then stops. It returns the integer formed up to that point.
- If no valid integer can be found at the beginning of the string, **parseInt** returns **NaN** (Not-a-Number).
- The radix parameter is optional, and if not provided, it's assumed to be 10 (decimal).

**parseFloat Function**:

- **parseFloat** is used to convert a string into a floating-point number (number with decimal points).
- It reads the string from left to right until it encounters a character that is not a part of a valid numeric representation, and then it stops.
- Like **parseInt**, **parseFloat** returns **NaN** if it can't find a valid numeric value.

Both **parseInt** and **parseFloat** are commonly used when dealing with user input, such as form fields or data from external sources, where values are typically provided as strings. These functions allow you to extract and work with numeric data in your JavaScript code.

It's important to handle error cases when using these functions since they can return **NaN** if the input string is not a valid number. You can check for **NaN** using **isNaN()** or perform additional validation to ensure you have valid numeric data before further processing.


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Original Source: https://www.mindstick.com/forum/160330/describe-the-parseint-and-parsefloat-functions-and-their-use-in-converting-strings-to-numbers

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