This function splits the string represented by string into array arr and returns the number of fields. The string value of the optional third argument fs specifies the field separator. fs is a list of break characters. For example: split("a:b;c", $arr, ":;") splits the string a:b;c into three fields, storing a in $arr[1], b in $arr[2], and c in $arr[3].)

The fs argument is optional; if omitted or null, the break characters are space, tab, and newline. Fields may be separated by multiple occurrences of white space. If fs is given, only a single instance of the field separator character separates each field. Any previous elements in the array arr are discarded before split stores the fields.