1. Java Syntax or Semantic Errors (Note: you cannot use missing semi-colon as your example.)

1. When you compile a Java program, you may encounter an error missing semi-colon, is it a syntax error or semantic error? Syntax error

2. Give two sample syntax error messages.

3. Give two sample semantic error messages.
4. 2.Use EBNF notation to describe the syntax of the following language constructs.
   1. A Java return statement, which could be either a return keyword followed by a semicolon, or a return keyword followed an expression then followed by a semicolon. Assume the grammar for expression has been defined as expr -> e
5. A Python return statement, either a return keyword, or return one or more expressions separated by comma.

(c) Based on your syntax definition in (b), is return x+y; a valid Python return statement?

4.Use the virtual machine codes (format shown below) to describe the operational semantics of the following C++ statements.

Virtual machine code format: (id here refers to any identifier/variable.)

id1 = id2

id = id1 op id2 (here op could be any arithmetic or logical operator.)

goto label

if id1 relop id2 goto label (here relop could be any relational operator)

total = 0;

for (int i=0; i

total = ++total + i * i

}