MATLAB Data Import/Export

Guidance for MATLAB data I/O — correct patterns for delimiters, locales, format-specific quirks, and common error messages.

When to Use

• Reading or writing CSV, Excel, Parquet, or JSON files in MATLAB with readtable/writetable/detectImportOptions
• Troubleshooting data I/O errors (misleading messages, "file not found" variants)
• Reading data from URLs or authenticated REST API endpoints
• Importing non-English locale data (European decimals, semicolons)
• Validating imported data for silent corruption (NaN, 65535, type widening)
• Reading compressed files or JSON with non-identifier keys
• Reading or writing text files (use readlines/writelines, not fopen/fgetl/fprintf)
• Reading or writing XML files (use MAXP provider, not legacy JAXP)

When NOT to Use