In lua, a string is iterated by character

Preface

In lua, when a string is a non-iteratable object and requires character-by-Character Processing of the most string, you can use string. sub (str, I,) to retrieve a single character. If there are other non-ASCII characters in the string, the length of non-ASCII characters is greater than 1 byte, such as UTF-8 characters, is stored in 3 byte, let's take a look at how to deal with these situations.

Description of the required standard library functions

String. sub (str, start, end) extracts the start-to-end characters from string str.

String. byte (char) to obtain the ASCII value of a char
ASCII character Iteration
Method: Extract ASCII characters one by one using string. sub
Running result:
"
Running result:
     
Summary
The string module of lua provides a limited number of string processing functions, but we can work with it.