How to fix 'class, interface, or enum expected' errors in Java? Comes with examples

Every Java programmer, whether beginner or experienced, encounters many errors while writing code. Generally, these errors are classified as run-time errors and compile-time errors. Run-time errors occur when running the code after successful compilation, while compile-time errors occur during compilation.

Expected class, interface or enumeration is an error thrown during source code compilation. This can happen for a number of reasons, one of which is misplaced curly braces. In this article, we will explore the causes of this error and the corresponding methods to fix expected errors on classes, interfaces, or enumerations.

Fix class, interface or enumeration expected errors in Java

Compilation errors indicate that our code does not follow the syntax rules of the Java programming language. A compiler-generated class, interface or enumeration expected error means that we have written something in the code that the Java compiler did not expect.

The expected cause of the class, interface, or enumeration error is:

• Curly bracket problem

• Undeclared class

• Defining methods outside the class scope

• Software package problem

Let us discuss these issues one by one and the ways we can fix this error

Reason 1: Curly bracket problem

As mentioned earlier, the most common reason for encountering class, interface, or enum expected errors is redundant or incorrectly placed curly braces. Maybe, we often encounter this error because of this reason, because it is very common for programmers to miss curly braces

Since we need to put the code in a class, interface or enumeration, when we mistakenly add extra curly braces in the code, the Java compiler expects a class, interface or enumeration

Example 1

The following example illustrates the error we will get if we place the braces incorrectly.

public class Example1 {
   public static void main(String[] args) {
      int nums = 0;
      nums++; // incrementing the value
      System.out.println("Incremented value: " + nums);
   }
}
} // adding extra curly brace to generate the error

Output

Example1.java:8: error: class, interface, enum, or record expected
} // adding extra curly braces to generate the error
^
1 error

Example 2

The following example illustrates how to fix a class, interface, or enumeration error by removing extraneous braces from the code.

public class Example2 {
   public static void main(String[] args) {
      int nums = 0;
      nums++; // incrementing the value
      System.out.println("Incremented value: " + nums);
   }
}

Output

Incremented value: 1

Reason 2: Class not declared

There may be situations where someone may forget to define a class and not include the code in the class at all. In this case, we may encounter class, interface or enumeration errors because as per Java guidelines, every code block must be defined within a class. So make sure you wrap each code block in a class

Reason 3: Defining methods outside the class scope

Another reason that may cause this error is that we mistakenly define a method outside the class scope.

Example 3

In the following example, we intentionally placed the 'main()' method outside the class to generate an error.

public class Example3 { }
// from below lines we will get error
   public static void main(String[] args) {
      int nums = 0;
      nums++; // incrementing the value
      System.out.println("Incremented value: " + nums);
   }

Output

Example3.java:3: error: class, interface, enum, or record expected
   public static void main(String[] args) {
                 ^
Example3.java:5: error: class, interface, enum, or record expected
      nums++; // incrementing the value
      ^
Example3.java:6: error: class, interface, enum, or record expected
      System.out.println("Incremented value: " + nums);
      ^
Example3.java:7: error: class, interface, enum, or record expected
   }
   ^
4 errors

Example 4

To fix the previous error, we just follow the example and put the 'main()' method inside the class.

public class Example4 {
   public static void main(String[] args) {
      int nums = 5;
      nums += 1; // incrementing the value
      System.out.println("Incremented value: " + nums);
   }
}

Output

Incremented value: 6

Cause 4: Package problem

We may encounter this problem when a Java programmer declares multiple packages in a single source code.

Example 5

In this example, we will declare two packages to generate errors.

package dummy1;
package dummy2;
public class Example5 {
   public static void main(String[] args) {
      int nums = 5;
      nums += 1; // incrementing the value
      System.out.println("Incremented value: " + nums);
   }
}

Output

dummy1/Example5.java:2: error: class, interface, enum, or record expected
package dummy2;
^
1 error

Example 6

In this example, we will remove one of the defined packages to fix the class, interface or enum expected error.

package dummy1;
public class Example6 {
   public static void main(String[] args) {
      int nums = 5;
      nums += 1; // incrementing the value
      System.out.println("Incremented value: " + nums);
   }
}

Output

Incremented value: 6

in conclusion

In this article, we looked at the expected errors for class, interface, or enumeration types through several example programs. We also discovered the cause of this error and the corresponding fix. Misplaced curly braces are the most common cause

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