To convert a negative number to a positive one in JavaScript, use the abs() method in JavaScript. The method returns the absolute value of a number.
Example
You can try to run the following code to convert a negative number to positive −
<html> <head> <title>JavaScript Math abs() Method</title> </head> <body> <script> var value = Math.abs(-1); document.write("First Test Value : " + value ); var value = Math.abs(null); document.write("<br />Second Test Value : " + value ); var value = Math.abs(20); document.write("<br />Third Test Value : " + value ); var value = Math.abs("string"); document.write("<br />Fourth Test Value : " + value ); </script> </body> </html>