convert string to number javascript isnan

Convert string to number javascript isnan how to#

I said “something” because it converts far more than just string representations of numbers and floats – it also works on the non-string values true, false, and null or an empty string. The is one of the fastest and easiest ways to convert something into a number.

Convert string to number javascript isnan how to#

How to Convert a String to a Number Using the Unary Plus Operator ( +) Note: The parseFloat() function will always return NaN when the character of the string cannot be converted to number: console.log(parseFloat('N0.0314E+2')) // NaN You can also use parseInt() for converting a non-integer number to an integer, while parseFloat() is the more powerful method as it can maintain floats and some mathematical logic: console.log(parseInt('12')) // 12Ĭonsole.log(parseInt('12.092')) // 12.092Ĭonsole.log(parseFloat('12.092')) // 12.092Ĭonsole.log(parseFloat(' 3.14 ')) // 3.14Ĭonsole.log(parseFloat('0.0314E+2')) // 3.14Ĭonsole.log(parseFloat('John Doe')) // NaNĪs usual this also works with variables: let age = '12' How to Convert a String to a Number Using the parseInt() and parseFloat() Functionsīoth the parseInt() and parseFloat() functions takes in a string as a parameter, and then convert that string to an integer/number. This is one of the easiest methods to use as it also works with decimal values and returns the values without manipulating them: let answer = '12.0' This also works with variables: let age = '12'

This method will also return NaN if the value can't be converted: console.log(Number('212')) // 212Ĭonsole.log(Number('0.0314E+2')) // 3.14Ĭonsole.log(Number('Hello World')) // NaN The Number function is a powerful method that you can use to convert strings or other values to the Number type. How to Convert a String to a Number Using the Number() Function Let’s now learn how to convert a string to a number. A good way to check if a variable is a string is by using the typeof operator: let name = 'John Doe' Suppose we have our string stored in a variable. In this article, we will learn how to convert string to number by going through the various methods and providing examples for each.īefore we begin, a common way to distinguish a string value is that it is always enclosed in either a single or double quote, whereas a number is not: 'John Doe' -> String This is just one of the many reasons you might want to learn how to convert a string to a number in JavaScript. And you'll need to correct those formats before performing certain actions on the data. When you're working with data from various sources, some of these data may arrive in the incorrect format.