Difference between In and Out parameters in Oracle functions

[Gaurav k]

Hi,

Can someone tell me exact difference between In and Out parameters used while creating a function in Oracle?

Thanks in advance.

[sainathsagar]

IN -- Value is used in a program.
It cannot be a variable but could be literal,express ion,value.

OUT -- Value is returned back from the program to the caller.
It must be a variable.

IN OUT-- It is combination of IN and OUT as name resembles.
It acts like a variable i.e., value can be used in
the program and then it can be returned back to the
caller from the program.

[arumurali]

IN parameters are passed as constants from the calling environment into the procedure.

OUT parameter values are returned from procedure to the calling environment.