A Visualization for Teaching Integer Coercion

Integer errors continue to create vulnerabilities. In fact, Integer Overflow or Wraparound is listed at position 11 in the 2020 CWE Top 25 Most Dangerous Software Weaknesses. This poster describes the Expression Evaluation (EE) visualization tool that helps students understand the type conversions that take place implicitly within a C program. This tool depicts step-wise the coercions that take place within the evaluation of a user specified expression with mixed integer type operands. The system enables students to create unlimited examples to test their understanding. The tool was evaluated in the classroom and shown to be easy to use and effective.