NumberFormatException in Java — What It Means and How to Fix It
What Java's NumberFormatException means and how to fix it.
Published November 2, 2026
NumberFormatException is thrown when code tries to convert a string into a number, but the string isn't a valid numeric format.
Key points
- Read the full stack trace from the top — it names the exact class, method, and line where the exception originated
Example
Integer.parseInt("abc"); // NumberFormatException