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next() and hasNext() methods of Scanner class

Mansukhdeep Thind
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Joined: Jul 27, 2010
Posts: 1157

Hi

The JLS says that "Both hasNext and next methods may block waiting for further input. Whether a hasNext method blocks has no connection to whether or not its associated next method will block." What does "being blocked waiting for input to be scanned mean"? Can someone perhaps quote an example code snippet ?


~ Mansukh
Campbell Ritchie
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Joined: Oct 13, 2005
Posts: 38517
    
  23
Try that with different inputs, including lots of whitespace and blank lines followed by the enter key.
Mansukhdeep Thind
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Joined: Jul 27, 2010
Posts: 1157

Campbell Ritchie wrote:Try that with different inputs, including lots of whitespace and blank lines followed by the enter key.


How do I provide blank lines as user input without making the cursor disappear. The cursor goes away when I press return key and it displays the first token as a result of executing the above snippet.
Campbell Ritchie
Sheriff

Joined: Oct 13, 2005
Posts: 38517
    
  23
Use the enter key before you write anything.
Mansukhdeep Thind
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Joined: Jul 27, 2010
Posts: 1157

Campbell Ritchie wrote:Use the enter key before you write anything.


OK. So unless and until I enter the input , the hasNext/next method will not be invoked. Got it. Thanks..
 
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