error: cannot find symbol

// BUG: misspelled variable name
String userName = "Alice";
System.out.println(usernName);  // cannot find symbol — usernName != userName

// FIX: use the exact declared name
System.out.println(userName);

// BUG: missing import
public class MyClass {
    public static void main(String[] args) {
        List<String> items = new ArrayList<>();  // cannot find symbol: List
    }
}

// FIX: add import at the top of the file
import java.util.List;
import java.util.ArrayList;

String name = "Alice";
int len = name.length();   // OK — length() exists on String
int cap = name.capacity(); // cannot find symbol — String has no capacity()

// FIX: use the correct method for the type
int cap = name.length();   // or use StringBuilder if you need capacity

// BUG: variable declared inside a block, used outside
if (true) {
    int x = 10;
}
System.out.println(x);  // cannot find symbol — x is out of scope

// FIX: declare in the outer scope
int x;
if (true) {
    x = 10;
}
System.out.println(x);

# Compile with the required JAR
javac -cp lib/commons-lang3-3.12.0.jar MyProgram.java

// BUG: wrong case
String s = "hello";
System.out.println(s.length);    // cannot find symbol — length is a METHOD

// FIX: Java is case-sensitive
System.out.println(s.length());  // method call — correct