Which statement about variable identifiers is correct based on common programming rules?

Which statement about variable identifiers is correct based on common programming rules?

• A. Spaces are allowed in names
• B. No spaces or symbols are allowed
• C. Only letters and numbers are allowed
• D. Underscores are allowed in names

Answer: (D)

Identifiers are names you give to storage locations in programs, and they follow specific rules about which characters can appear. In most languages you can include letters and digits, and you’re also allowed to use underscores as part of the name. Spaces and most special symbols aren’t allowed in identifiers, which is why you’ll see names like total_count or user_id rather than something with spaces or punctuation. The allowance of underscores helps keep identifiers readable, especially when you want to separate words without introducing spaces. This is why the statement about underscores being allowed in names is correct and widely applicable across common programming languages.

Identifiers are names you give to storage locations in programs, and they follow specific rules about which characters can appear. In most languages you can include letters and digits, and you’re also allowed to use underscores as part of the name. Spaces and most special symbols aren’t allowed in identifiers, which is why you’ll see names like total_count or user_id rather than something with spaces or punctuation. The allowance of underscores helps keep identifiers readable, especially when you want to separate words without introducing spaces. This is why the statement about underscores being allowed in names is correct and widely applicable across common programming languages.