POSIX regular expressions(SPLIT)

split - 
         This function divides strings based on the pattern that it searches for and stored the separated
text into an array. The searches are case-sensitive when dealing with alphabetical characters.

<?php
$csv_text = "5, \"Amsterdam\", \"NLD\", \"Noord-Holland\",
731200";
$csv_array = split("[,]",$csv_text);
foreach ($csv_array as $csv_column) {
print "$csv_column<br>";
}
?>

The script above would create an array called $csv_row that contains the following element: [0] =
5, [1]="Amsterdam", [2]="NLD", [3]="Noord-Holland", [4]=731200). The foreach iterative control
statement would print each of these elements on the screen on their own lines. A third component can
be placed in the split function that would limit the number of array elements that would be created.
By adding 3 to the split function in the above script (split("[,]",$csv_text, 3) the array
elements that would be created would consist of: [0]=5, [1]="Amsterdam", [2]="NLD", "Noord-
Holland", 731200.

• spliti -
            This function is identical to split(), except that it is case insensitive when searching.