The variables in algebra and in computer program-(A)
Here we should digress a little
To fully understand the use of “memory houses”
We know that main memory board is like a city
With hundreds of thousands of houses
All neatly connected by a maze
Of perpendicular and parallel roads.
Each memory house has eight or sixteen chambers
All in a row to make the memory house
Look like a long military barrack
The row of chambers are also generally interconnected
The manufacturer allots a “house number”
To every memory house just like the city municipality does.
But these “house numbers” are not directly used by us.
We recognize many buildings with special names
Such as hotel,school,hospital,cinema hall etc
But do not refer to them with their house numbers
Which are allotted by the municipality.
Similarly in the big city of “memory houses”
We select a few dozen “memory houses”
In a particular area of the main memory board
And give them formal names like X,Y and Z
These names are like the variables X,Y,Z in algebra.
We use to indicate unknown quantities.
In different problems the variables take different values.
X may denote 2 and 200 and 2000 in different problems.
Similarly in the memory houses selected by us
Different numbers may reside in different “computer programs”
In one program the number 2 lives in memory house x
In next program the number 9 lives there
And in still another program the number 27 lives there.
A simple program is so similar to an algebra problem
In mathematics we call it “problem”
And in computer lore we call it a “program”.
In small computer programs
We use just three or four memory houses
Or at the most a dozen memory houses.
However we may require a few more memory houses
As the program develops.
The CPU itself may use a few memory houses
To keep interim datawith out us even being aware.
In a computer program
The first thing we do is to “declare variables”
It means we identify some memory houses
And give them specific names like X,Y,Z.
In businessmen’s computers
They may declare the variables with names
“Salary”, “interest”, “profit”, “commission” etc!
In a cricketer’s computer the variables may be
The computer does not mind in the least the very long names.
After declaring variables in algebra
We mention a formula to solve the problem.
In algebra the formula is generally very short
But in computer programs
We develop a process and so
There are generally a large number of steps
To explain the step by step procedure.
Perhaps a dozen steps sufficed
To develop an old time computerprogram.
But a few hundred or few thousand steps
May be required to write new programs.
There are very advanced and accurate rules
To control and ensure accuracy
In the structure of such long programs.
Any way solving a simple computer program
Is quite similar to an algebra problem.
Weshould in the beginning of program itself
Select separate memory houses
To accommodate the answers too.