Splits a string into a Hash String (array of strings) by separating the string into substrings using regular expressions.
Split hs[] = sexp, pattern [, max]
hs[]:Hash String
sexp, pattern:sexp
max:iexp
Split returns the substrings of sexp in a Hash String, a list of strings. The Hash can be iterated over using For Each or a simple For Next. pattern is the string used to identify substring limits using a regular expression. The optional argument max specifies the maximum number of substrings to return. Although pattern can be a complex regular expression, it can also be a simple string that defines where the splits take place. For instance, the following example splits a string at a space character:
Dim hs As Hash String, s As String
Split hs[] = "This is a test", " "
For Each s In hs[]
Debug Each ` s
Next
Debug.Show
This prints in the Output window:
1 This
2 is
3 a
4 test
Now, if the string contained a double space before the word test, there would be five elements found of which the fourth is an empty string.
Dim hs As Hash String
Split hs[] = "This is a test", " "
Debug hs[%]' prints 5
Debug.Show
Often, this is not wanted. In that case regular expressions solve the problem elegantly. The pattern argument can be changed to a group of spaces: "[ ]+". See reMatch for an overview of the patterns.
Split hs[] = "This is a test", "[ ]+"
Local h As Hash String, s As String
Split h[] = "name,surname;street,12,"#9",Cologne,,Fax: 0111-1234567 ", "\s*[,;]\s*"
For Each s In h[]
Debug Each`s
Next
Debug.Show
// this command splits the string into
h[% 1] = "name"
h[% 2] = "surname"
h[% 3] = "street"
h[% 4] = "12"
h[% 5] = ""
h[% 6] = "Cologne"
h[% 7] = ""
h[% 8] = "Fax: 0111-1234567"
The example shows a summary of personal information in a string separated by spaces, commas, tabs, and other white spaces. The search pattern is defined as: any number of spaces and/or tabs, then a comma or a semicolon, then again optional spaces or tabs. The string is separated with empty strings for missing details (commas, succeeding one another, with or without spaces or tabs between).
The VB function ar$() = Split(sexp[, delimiter[, max[, compare]]]) is easily converted to GFA-BASIC 32. Rather than a string array, GFA-BASIC 32 uses a Hash String.
| VB Split Function | GFA-BASIC 32 Split Command |
|---|---|
| Dim ar() As String Dim sexp As String Dim delim$ = " " ar = Split(sexp, delim, ,0) For i = 0 to UBound(ar()) Print ar(i) Next |
Dim hs As Hash String Dim sexp As String Dim delim$ = " " Dim Cmp = Mode(Compare) Mode Compare 0 Split hs[] = sexp, delim Mode Compare Cmp For i = 1 To hs[%] Print hs[% i] Next |
The delimiter argument may contain only one character in VB. The compare mode indicates the kind of comparison to use when evaluating substrings. In GFA-BASIC 32 use the Mode Compare before executing the Split command. After executing the Mode Compare should be restored.
Join, reMatch, reSub, preMatch, Hash
{Created by Sjouke Hamstra; Last updated: 23/10/2014 by James Gaite}