Coding standards is a set of guidelines and best practices to create high-quality, readable, and maintainable code with minimal errors. Knowing coding standards has become a crucial aspect of software engineering ---especially in the software industry for large-scale codebase project--- Yet, programming courses at the university level fall short in adequately preparing their students in this aspect. In this study, we identify code quality issues in introductory programming courses, detected by CheckStyle for Java programming assignments. We also employ natural language processing to categorize programming errors based on their semantic similarity. Our study reveals common issues such as spacing problems and non-compliance with naming conventions, exacerbated by factors like having tight schedules and limited grading emphasis.