Labeled Statement block in Java?

Question

I was browsing through some of the base Java objects when I found a section of code surrounded by a scan: {} block. The following code is from the toLowerCase()

Answer 1

It is a labeled block. where scan: is a label. It is commonly used when breaking/continue in case you have multiple loops. In this case break scan; simply breaks outta the labeled block(scan) when executed.

Answer 2

Here, scan: is simply a label. The break <label> syntax allows one to break out of outer loops, and to simulate some forms of the goto statement. The syntax is documented in the JLS:

A break statement with label Identifier attempts to transfer control to the enclosing labeled statement (§14.7) that has the same Identifier as its label; this statement, which is called the break target, then immediately completes normally. In this case, the break target need not be a switch, while, do, or for statement.

Answer 3

You can set a label to break / or continue from within multiple loops deep.

Example

 outer:
 for(int i=...){
   for(int j=..){
     ...
     break outer; // leaves both loops   

   } 

 }

Answer 4

It is a label. It is a indicator for flow control.

If you look at your code, you see below

 break scan;

When this happens, the flow exits completely the scan block.

By the way, it can be any identifier, scan is not a keyword at all.