FromSitesTree.com, SCJP/OCJP

SCJP: Flow controls and exception #Java Short Notes #SCJP

Leave a comment

Flow Control and ExceptionsFlow control statements

  • Conditional: if, if-else and switch-case
  • Looping: for, while, do-while
  • Exception handling: try-catch-finally, throw
  • Ad hoc flow control: break, continue with or without labels
switch statement
         switch(expression){ 
        case ConstantExpression: statement(s); 
        case ConstantExpression: statement(s);
        .
        .
        .
        default: statement(s);
      }

  • expression: must be char, byte, short, or int, or a compile-time error occurs
  • long primitive can be used if type casted to int
  • Object reference cannot be used as expression
  • Every case expression must be unique
  • break statement may be used at the end of a case statement, to discontinue execution.
  • There can be at most only one default statement.
  • The order of case statements and default can be anything.

break and continue

  • A break statement transfers the control out of an enclosing statement. break used within a loop breaks the execution of the current loop. In case of nested loops, the break statement passes the control to the immediate outer loop.
  • A continue statement breaks the current iteration and moves to next iteration.
  • break and continue with labels.
    • Labels specify the target (statement) for continue and break
    • continue with label does not jump to the labeled statement but instead jumps to the end of the labeled loop.
    • Same label identifiers can be reused multiple times as long as they are not nested.
    • Label names do not conflict with the same named identifier(variable, method or class name).

Checked and Unchecked Exceptions

Checked Exceptions

  • Checked Exceptions are checked by the compiler to see if these exceptions are properly caught or specified. If not, the code will fail to compile
  • Checked exception forces client program to deal with the scenario in which an exception may be thrown
  • Checked exceptions must be either declared or caught at compile time

Unchecked Exceptions

  • Unchecked exceptions are RuntimeException and all of its subclasses.
  • Class java.lang.Error and its subclasses also are unchecked.
  • Unchecked Exceptions are not checked by the compiler.
  • Runtime exceptions do not need to be caught or declared.

From: http://sitestree.com/?p=4864
Categories:Java Short Notes, SCJP
Tags:
Post Data:2008-08-25 00:56:33

Shop Online: https://www.ShopForSoul.com/
(Big Data, Cloud, Security, Machine Learning): Courses: http://Training.SitesTree.com
In Bengali: http://Bangla.SaLearningSchool.com
http://SitesTree.com
8112223 Canada Inc./JustEtc: http://JustEtc.net (Software/Web/Mobile/Big-Data/Machine Learning)
Shop Online: https://www.ShopForSoul.com/
Medium: https://medium.com/@SayedAhmedCanada

Leave a Reply