How to Use the split function in js

Split
Split is opposite to join, used to split a string into a string array.
StringObject. split (a, B) is its syntax.

A is a required decision to separate from.
B is not required. Optional. This parameter specifies the maximum length of the returned array. If this parameter is set, no more substrings are returned than the array specified by this parameter. If this parameter is not set, the entire string is split, regardless of its length.

Note that the returned array does not include a itself;

Tips and comments
NOTE: If an empty string ("") is used as a, each character in the stringObject is separated.
Note: The operations executed by String. split () are the opposite to those executed by Array. join.

Example
Var str = "Hello World! ";
Document. write (str. split ("") + "<br/> ");
Document. write (str. split ("") + "<br/> ");
Document. write (str. split ("", 3) + "<br/> ");

Return
H, e, l, l, o, W, o, r, l, d ,!
Hello, World!
H, e, l