Atof (converting strings to floating-point numbers)

Atoi (converting a string into an integer)

Atol (converting a string into an integer)

Strtod (Converts a string to a floating-point number)

Strtol (Converts a string to an integer)

Strtoul (Converts a string to an unsigned long integer)

Number to string (stdio.h header file):

Sprintf (format output, which can convert any type of variable into a string)