- Gets the substring of a string.
- str
-
- The string.
- start
-
- The starting index, counting from 1 at the left, or -1 at the right.
- end
-
- The ending index, counting from 1 at the left, or -1 at the right. (default -1)
The start and end indices are inclusive, which is to say the characters at both indices will be included in the result. To extract a single character, use the same value for both, e.g. sub(s,i,i).
Note that negative indices can be very useful. For instance, to get the rightmost four characters of a string, one simply writes sub(s,-4).
Notes[]
Individual characters can be extracted from a string by supplying the same index for both start and end. The result is still technically a string, but with a length of exactly 1. This is the way Lua typically represents individual characters.
PICO-8 adds the ability to represent characters as their ordinal value, a whole number in the range 0..255. There are two calls that can convert back and forth between the two representations:
- To convert an ordinal number n to its single-character string counterpart, use
chr(n).
- To convert a single-character string c to its ordinal number counterpart, use
ord(c).
- To convert a single character at index i in a longer string s to its ordinal number, use
ord(s, i).
Examples[]
print(sub("hello there", 1, 5)) -- hello
print(sub("hello there", -5)) -- there
print(sub("hello there", 7, 7)) -- t
