stdlib.h 提供許多 function 讓字串可以轉換為數字型別
output | function | input |
float | strtof | (const char *, char **) |
double | strtod | (const char *, char **) |
long double | strtold | (const char *, char **) |
long | strtol | (const char *, char **, int) |
long long | strtoll | (const char *, char **, int) |
unsigned long | strtoul | (const char *, char **, int) |
unsigned long long | strtoull | (const char *, char **, int) |
long long | strtoq | (const char *, char **, int) |
unsigned long long | strtouq | (const char *, char **, int) |
ex ⇒ strtol ⇒ 轉為 long int