CODEWITHSUNDEEP
javajava.util.scanner
Alex Lay-Calvert
Alex Lay-Calvert

Reputation: 67

What is the advantage of using multiple scanners?

What is the advantage or use of using multiple scanner objects in a program? 

Scanner sc = new Scanner(System.in);

as opposed to something like

Scanner sc1 = new Scanner(System.in);
Scanner sc2 = new Scanner(System.in);

in the same program.

Upvotes: 3

Views: 77

Answers (1)

Hovercraft Full Of Eels
Hovercraft Full Of Eels

Reputation: 285405

I can see no advantage to the second bit of code:

Scanner sc1 = new Scanner(System.in);
Scanner sc2 = new Scanner(System.in);

and in fact there is some risk, risk if you close one Scanner (and thus the System.in) before the other Scanner is done using it.

Instead, I can definitely see using more than one Scanner at times, but only one primary Scanner linking to System.in. Other Scanners can parse a line obtained. For example, use the main Scanner to get each line of text, and then use a second Scanner that has been fed the individual lines to parse the information held in the lines.

e.g.,

Scanner sc = new Scanner(System.in); 
while (sc.hasNextLine()) {
    String line = sc.nextLine();
    Scanner lineScanner = new Scanner(line);
    //.... parse line...
    lineScanner.close();
}
sc.close();

Upvotes: 9

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