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An explanation and example creating versatile code using typedef within the C++ programming language.

Overview

Everyone seeks of ways to be more efficient in what they do. A farmer uses a tractor instead of a horse. A construction worker uses an air powered nail gun instead of a hammer. Programmers are no different than others, in that they are constantly improving their ability to produce correctly working programs. Some aspect of this is the use of modular/structured programming, proper documentation and following industry rules for a specific programming language. One example of efficient coding is letting the computer count the number of elements in an array. If we define an array:

int ages[] = {33,32,10,3};

We can use the following expression to calculate the number of members in the array:

sizeof ages / sizeof ages[0]

This type of flexible coding allows us to change the members of the array by adding or subtracting a values, like this:

int ages[] = {57,33,32,3,1};

Thus, we don't have to modify our code that uses the expression that calculates the number of member in the array.

One use of the typedef is to allow us to write code that can be quickly changed to handle different data types. There are several integer and floating-point data types that all store number values with different domains. If we write our code using some typedef statement, then our code becomes versatile . By changing only our typedef commands, our code can be used to process data of a different data type. This is demonstrated within the demo file provided, thus you need to study this material in conjunction with the demo program.

Demonstration program in c++

Creating a folder or sub-folder for source code files

Depending on your compiler/IDE, you should decide where to download and store source code files for processing. Prudence dictates that you create these folders as needed prior to downloading source code files. A suggested sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:

  • Demo_Programs

If you have not done so, please create the folder(s) and/or sub-folder(s) as appropriate.

Download the demo program

Download and store the following file(s) to your storage device in the appropriate folder(s). Following the methods of your compiler/IDE, compile and run the program(s). Study the source code file(s) in conjunction with other learning materials. You may need to right click on the link and select "Save Target As" in order to download the file.

Download from Connexions: Demo_Versatile_Array_Functions.cpp

Download from Connexions: Demo_Farm_Acres_Input.txt

Download from Connexions: Demo_Deposit_Checks_Input.txt

Definitions

versatile
Easily modifying code to handle another data type.
flexible coding
Using the sizeof operator to calculate the number of members in an array.
typedef
Allows the programmer to create an alias, or synonym, for an existing data type.

Questions & Answers

how do we prove the quadratic formular
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4
Trista
x-2y+3z=-3 2x-y+z=7 -x+3y-z=6
Sidiki Reply
Need help solving this problem (2/7)^-2
Simone Reply
x+2y-z=7
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what is the coefficient of -4×
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-1
Shedrak
the operation * is x * y =x + y/ 1+(x × y) show if the operation is commutative if x × y is not equal to -1
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An investment account was opened with an initial deposit of $9,600 and earns 7.4% interest, compounded continuously. How much will the account be worth after 15 years?
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lim x to infinity e^1-e^-1/log(1+x)
given eccentricity and a point find the equiation
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12, 17, 22.... 25th term
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12, 17, 22.... 25th term
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Absolutely, for me. My problems with math started in First grade...involving a nun Sister Anastasia, bad vision, talking & getting expelled from Catholic school. When it comes to math I just can't focus and all I can hear is our family silverware banging and clanging on the pink Formica table.
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find the 15th term of the geometric sequince whose first is 18 and last term of 387
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I know this work
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The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
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If f(x) = x-2 then, f(3) when 5f(x+1) 5((3-2)+1) 5(1+1) 5(2) 10
Augustine
how do they get the third part x = (32)5/4
kinnecy Reply
make 5/4 into a mixed number, make that a decimal, and then multiply 32 by the decimal 5/4 turns out to be
AJ
how
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A soccer field is a rectangle 130 meters wide and 110 meters long. The coach asks players to run from one corner to the other corner diagonally across. What is that distance, to the nearest tenths place.
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Jeannette has $5 and $10 bills in her wallet. The number of fives is three more than six times the number of tens. Let t represent the number of tens. Write an expression for the number of fives.
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Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
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Source:  OpenStax, Programming fundamentals - a modular structured approach using c++. OpenStax CNX. Jan 10, 2013 Download for free at http://cnx.org/content/col10621/1.22
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