Which regular expression, inserted at line 12, correctly splits test into "Test A", "Test B", and "Test C"?

Given:

11. String test = "Test A. Test B. Test C.";
12. // insert code here
13. String[] result = test.split(regex);



A. String regex = "";
B. String regex = " ";
C. String regex = ".*";
D. String regex = "\\s";
E. String regex = "\\.\\s*";
F. String regex = "\\w[ \.] +";









Answer: E

Explanation:

Remember that if you need to create a String that contains a double quote " or a backslash \ you need to add an escape character first.If you need to search for periods (.) in your source data and If you just put a period in the regex expression, you get the "any character" behavior. 

So, what if you try \. ? Now the Java compiler thinks you're trying to create an escape sequence that doesn’t exist. 

The correct syntax to do so is 
String s = "ab.cde.fg";
String[] tokens = s.split("\\.");
which gives Output as :
abcdefg

Removes .(dot) and joins them.

Similarly \\s refers any occurrence of White Space and \\s* refers to occurrence of White Space character zero or more times .

String regex = "\\.\\s*"; is used which tells compiler that when both .(dot) and any number of White  Space occurs together then remove them .Therefore output will be Test ATest BTest C .