What can a Java identifier begin with?

What can a Java identifier begin with?

• A. A digit
• B. A letter
• C. An underscore
• D. A letter or an underscore (_)

Answer: (D)

In Java, an identifier (like a variable or method name) cannot start with a digit. The first character must be a letter (any Unicode letter) or an underscore, and later characters can be letters, digits, or underscores (with the dollar sign also allowed in real code, though that detail isn’t always emphasized). Because the question focuses on valid starting characters, the option that includes both a letter and an underscore reflects the valid starting choices most directly.

In Java, an identifier (like a variable or method name) cannot start with a digit. The first character must be a letter (any Unicode letter) or an underscore, and later characters can be letters, digits, or underscores (with the dollar sign also allowed in real code, though that detail isn’t always emphasized). Because the question focuses on valid starting characters, the option that includes both a letter and an underscore reflects the valid starting choices most directly.