When to use local variables and shared variables?

[helpmePls]

Dear Labview gurus,

What is the difference between local variables and shared variables? What are the appropriate situations in which I should use shared variables?

[Jorge_Amaral]

See if the informarion suppied on ni website it's enough for you~:

shared variable:
http://zone.ni.com/devzone/cda/tut/p/id/4679
(normaly to pass values in the network)

local variable:
It's used to pass values inside a .vi

[mattyG]

What is the difference between a single-process shared variable and a local variable?

[BillMe]

A local variable is local to the VI in which it's declared and used. It has no scope outside that one VI.

A single process shared variable can pass information throughout a single instance of your application. It has no scope outside that single instance.

[altenbach]

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@mattyG wrote:
What is the difference between a single-process shared variable and a local variable?

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A single process shared variable is more like a global variable, because it can be accessed from any VI in your hierarchy. Local variables are strictly local to the single VI where they reside.

Shared variables are a relatively new feature, while local and global variables are ancient. As such, shared variables are in many ways more modern and integrate better into state-of-the-art coding guidelines.

• Shared variables contain error terminals so you can enforce execution order. local variables have no such thing.
• A shared variable can stand on its own, while a local variable is always tied to a front panel object.
• You need a project for shared varaibles.

You can easily turn a single process shared variable into a network shared variable later in the development, without the need to rewrite any code.