What is scope and lifetime of a variable?  

A scope of an variable is the part oof the program or the block of the program in which it is visible but outside that block the variable doesnot exist. Lifetime of a variable defines the time for whcih the variable exist in a program. A block is begun with an opening curly brace and ended by a closing curly brace. A block defines a scope. Thus, each time you start a new block, you are creating a new scope. A scope determines what objects are visible to other parts of your program. It also determines the lifetime of those objects. The scope defined by a method begins with its opening curly brace. However, if that method has parameters, they too are included within the method’s scope.

Answered by saixaero at 7:44 PM on February 11, 2008

Well , When you declare a variable within a procedure, only code within that procedure can read or change the value of that variable: Its scope is local to that procedure. Sometimes, however, you want to use a variable with a broader scope, one whose value is available to all procedures within the same module, or even to all the procedures in all modules. With Visual Basic, you can specify the scope of a variable when you declare it.
Scope of Variables

Depending on how you declare a variable, its either a procedure-level or a module-level variable.
Scope is Private or Public

Procedure-level Variables are private to the procedure in which they appear. Not applicable. You cant declare public variables within a procedure.
Module-level Variables are private to the module in which they appear. Variables are available to all modules.

for more information , visit the source site :

http://msdn.microsoft.com/arch ive/default.asp?url=/archive/en-us/ office97/html/scopelifetimeofvariab les.asp

Answered by alokgupta14 at 7:36 PM on February 03, 2008

When you declare a variable within a procedure, only code within that procedure can read or change the value of that variable: Its scope is local to that procedure. Sometimes, however, you want to use a variable with a broader scope, one whose value is available to all procedures within the same module, or even to all the procedures in all modules. With Visual Basic, you can specify the scope of a variable when you declare it.

Answered by Deepak at 3:38 AM on February 03, 2008

Scope is the scope of an identifier is the portion of the program text in which that identifier is accessible. Lifetime of an object is the time period from the time when the object is created till the time it is destroyed.

Answered by Nisha at 8:45 PM on February 02, 2008

Java class variables have six possible levels of visibility to other classes: Java Scope
Scope Visibility Purpose
published visible to external users of a Javabean Javabean properties and methods. There is no way to declare a method published in the Java source. You use a special getXXX/setXXX naming convention and write a separate declaration file.
public visible to all classes methods and variables of interest to users of the class.
protected visible to classes outside the package that inherit the class, also to all classes in the package. methods and variables of interests to third parties who may extend your class.
default
aka package
aka friendly visible to all classes of the package. methods and variables involved in cross-class communication within the package.
private visible only within the class, not by inheritors, not by other classes in the package. Variables and methods that should not or would not be changed by someone extending the class. Proper functioning of the class depends on them working precisely as written.
local visible only to the block of the method in which the variables were declared. Temporary working variables.

Answered by Shilpa Behl at 6:02 PM on February 02, 2008