Password Validation in Java: Explanation & Practice

Problem summary

Create password validator that checks length, uppercase, lowercase, and digit requirements.

Starter code

// Password must have:
// - At least 8 characters
// - At least one uppercase
// - At least one lowercase
// - At least one digit

public class Main {
    public static void main(String[] args) {
        String password = "weak"; // Test case 1
        
        // Validate and report all failures
    }
}

Expected output and test cases

• Multiple failures

  Invalid: Too short, No uppercase, No digit

• Single failure

  Invalid: No uppercase

• Valid password

  Password valid

Hints

1. Check each rule separately
2. Collect all failures
3. Report all issues at once

Related Exception Handling exercises

• Practice Exception Propagation in Java
• Practice Age Range Validator in Java
• Practice Null Handling in Java

Practice all Exception Handling exercises · Run this idea in the Java compiler