The following is a list of compilation errors that the compiler generates when it encounters invalid code. A subset of these errors is detected only when compiling code in strict mode. Strict mode adds three constraints not found in the standard language:

• Expressions have static types and type errors are verification errors.
• Additional verification rules catch common programming errors.
• Verification errors are reported ahead of time. These are the verification errors that occur only in strict mode:
• Function call signature matching, which checks the number of parameters supplied and their types.
• Duplicate definition conflicts.
• Unbound references, which occur when accessing methods or properties that are not defined at compile time.
• Dynamically adding properties on sealed objects.
• Writing to constant variables.
• Deleting fixed properties.
• Comparison expressions that use incompatible types.
• Unfound packages.

	Code	Message	Description