What is a subroutine and how is it used?

In computer programming, a subroutine is a sequence of program instructions that performs a specific task, packaged as a unit. This unit can then be used in programs wherever that particular task should be performed.

What is difference between subroutine and function?

A function commonly carries out some calculations and reports the result to the caller. Subroutines perform a task but do not report anything to the calling program. A function cannot change the value of the actual arguments . A subroutine can change the value of the actual argument.

Where are nested tables available?

A nested table can be stored in a database column. It can further be used for simplifying SQL operations where you join a single-column table with a larger table.

What is meant by nested subroutines?

A nested subroutine is a subroutine that is called from within some other subroutine. Now a nested subroutine can invoke itself some other subroutine(s). Therefore we can talk about the depth of subroutine nestings. Subroutines are seldom nested more than a few layers deep.

Why are subroutines used?

Subroutines make programs shorter as well as easier to read and understand, because they break program code into smaller sections. You can test procedures or functions separately, rather than having to test the whole program. This makes programs easier to debug.

Are subroutines functions?

In many aspects, subroutines and functions are the same. However, they are different in a few major aspects, such as how to call them and the way they return values. To call a subroutine, use the CALL instruction followed by the subroutine name (label or program member name).

Can you call a subroutine from within a subroutine?

Normally you put all procedures in a module and then use the module. If, as your question suggest make all procedures as internal to your main program, there is no problem in calling them. Just invoke them normally using the call statement, or by using the function name with the argument list.

What is the difference between routine and subroutine?

is that subroutine is (computer science) a section of code, called by the main body of a program, that implements a task while it may be used at more than one point in a program, it need not be while routine is a course of action to be followed regularly; a standard procedure.