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Jan 3, 2024 · Fundamentals

Master C String‑Number Conversion Functions: atof, atoi, atol, strtod, strtol, and More

This guide consolidates essential C standard library functions for converting between strings and numeric types—including atof, atoi, atol, gcvt, strtod, strtol, strtoul, toascii, tolower, and toupper—detailing their headers, prototypes, behavior, and practical code examples with expected outputs.