split() -- split a string into many strings
The split-function requires a string (containing the text to be split), a reference to a string-array (which will receive the resulting strings, i.e. the tokens) and an optional string (with a set of characters, at which to split, i.e. the delimiters).
The split-function regards its first argument (a string) as a list of tokens separated by delimiters and it will store the list of tokens within the array-reference you have supplied. Note, that the array, which is passed as a reference (w$() in the synopsis), will be resized accordingly, so that you don't have to figure out the number of tokens in advance. The element at position zero (i.e. w$(0)) will not be used.
Normally (i.e. if you omit the third, which is the delimiter-argument) the function will regard space or tab as delimiters for tokens; however by supplying a third argument, you may split at any single of the characters within this string. E.g. if you supply ":;" as the third argument, then colon (:) or semicolon (;) will delimit tokens.
Note, that a sequence of separator-characters will produce a sequence of empty tokens; that way, the number of tokens returned will always be one plus the number of separator characters contained within the string. Refer to the closely related token-function, if you do not like this behaviour. In some way, the split-function focuses on the separators (other than the token-function, which focuses on the tokens), hence its name.
The second argument is a reference on a string-array, where the tokens will be stored; this array will be expanded (or shrinked) to have room for all tokens, if necessary.
The first argument finally contains the text, that will be split into tokens. The split-function returns the number of tokens that have been found.
Please see the examples below for some hints on the exact behaviour of the split-function and how it differs from the token-function:
print "This program will help you to understand, how the"
print "split()-function exactly works and how it behaves"
print "in certain special cases."
print "Please enter a line containing tokens separated"
print "by either '=' or '-'"
input "Please enter a line: " l$
print num," Tokens: "
for a=1 to num
if (t$(a)="") then
if (a<num) print ","
This program prints the following output:
Please enter a line: a
1 Tokens: a
Please enter a line:
Please enter a line: ab
1 Tokens: ab
Please enter a line: a=b
2 Tokens: a,b
Please enter a line: a-
2 Tokens: a,(EMPTY)
Please enter a line: a-=
3 Tokens: a,(EMPTY),(EMPTY)
Please enter a line: =a-
3 Tokens: (EMPTY),a,(EMPTY)
Please enter a line: a=-b
3 Tokens: a,(EMPTY),b
Please enter a line: a--b-
4 Tokens: a,(EMPTY),b,(EMPTY)
Please enter a line: -a==b-c==
7 Tokens: (EMPTY),a,(EMPTY),b,c,(EMPTY),(EMPTY)