strings

string sub ranging - comments by Grey@TMI-2

You can take a substring from a variable ( str ) buy using the substring operation ( str[n1..n2] ). Positive values are taken from the left and values with < from the right. If a value is greater than the length of the string it will be treated as being equal to the length of the string.

If the two values are equal ( str[n1..n1] ) then the character at that position ( n1 ) is returned. If both values point to positions beyond the same end of the string the null string ( "" ) is returned. If the position pointed to by the first value is after the one pointed to by the second then the null string is also returned.

Examples:

str = "abcdefg"

str[0..0] ==       "a"
str[0..<1] ==      "abcdefg"
str[<4..<2] ==     "def"
str[<7..6] ==      "abcdefg"
str[3..2] ==       ""
str[2..] ==        "cdefg"