How to split a string into an array in Bash?
Note that the characters in $IFS are treated individually as separators so that in this case fields may be separated by either a comma or a space rather than the sequence of the two characters. Interestingly though, empty fields aren't created when comma-space appears in the input because the space is treated specially.
The last example is useful because Bash arrays are sparse. In other words, you can delete an element or add an element and then the indices are not contiguous.
As mentioned above, arrays can be sparse so you shouldn't use the length to get the last element. Here's how you can in Bash 4.2 and later:
Larger negative offsets select farther from the end of the array. Note the space before the minus sign in the older form. It is required.
1: This is a misuse of $IFS. The value of the $IFS variable is not taken as a single variable-length string separator, rather it is taken as a set of single-character string separators, where each field that read splits off from the input line can be terminated by any character in the set (comma or space, in this example).
