In C/C++ style notation, which of the following is NOT an integer constant?

Introduction / Context:
Literals (constants) in programming languages are categorized by type—integer, floating-point, character, string, etc. Being able to recognize integer vs. floating-point constants is foundational for understanding type rules and compiler behavior.

Given Data / Assumptions:

• We use conventional C/C++ syntax for numeric literals.
• Leading sign (+ or −) is treated as a unary operator applied to a literal.
• Presence of a decimal point indicates a floating-point literal unless otherwise suffixed.

Concept / Approach:

An integer constant contains only digits (optionally with base prefixes/suffixes) and no decimal point. A floating-point constant contains a decimal point and/or exponent part with a fractional component. Thus, any literal with a decimal point like '-8.1' is not an integer constant.

Step-by-Step Solution:

Verification / Alternative check:

Compiling small snippets confirms types via typeof or format specifiers (e.g., printf with %d vs. %f).

Why Other Options Are Wrong:

• 0, −8, +1074, 42: valid integer constants in typical languages.

Common Pitfalls:

Treating a leading '+' as invalid—most languages accept it; confusing a minus sign with part of the literal vs. unary negation (type remains integer).

Final Answer:

-8.1