Sets the string to the character representation of the
number x.
str_for_num generates strings with 3 decimals and A7.20 str_for_float generates strings with 6 decimals.
Parameters:
STRING*
STRING pointer, or NULL for returning a temporary string.
x
var, long, or double variable.
Returns:
STRING*
Speed:
Fast
Example:
STRING* s = " ";
...
str_for_num(s,sqrt(2)); // now s == "1.414"