What Do I Need To Know Before Becoming A Programmer

//Declaration of our variables
double grossSalary = 5000;
double socialSecurity;
double taxes;
double netSalary;

//Calculate the Social security
socialSecurity = grossSalary * 0.1;

//Calculate the Taxes
taxes = grossSalary * 0.2;

//Calculate the net salary
netSalary = grossSalary - socialSecurity - taxes;

//Show the result
Console.WriteLine("The Salary is " + netSalary);

It is exactly the same for programming languages. We use the best suitable one for the environment. For example, if we are using Microsoft, it’s better to use c#. If we want to make a program that interacts directly with the hardware, C language is the best choice (for developing drivers for example or electronic components …), but if we want to develop a program that gives a user some functionalities, it is may be to do it with javascript or another one that can interact with tools that provide a nice user interface features ...

Once we understood what means a programming language, we have to use it. When we write words in a specific language, we obtain a text that is called Source Code. The Source Code is the representation of an algorithm in a specific programming language.

But… there still is something missing …How is this Source code understood by the machine? Can we write the source code in Microsoft Word and then execute it?

A compiler

In this section, we will detail the part "understood by a specific compiler" of our definition in the first section.

When you buy a new computer, it will not be able to understand the source code that you write. You need to install some tools to give your code some meaning.

So first thing to do when we want to become a programmer is to choose the language that we want to use. Then prepare the computer by installing tools that will allow us to program.

These tools are the editor and the compiler.

The compiler will check everything you code; it will parse your code and analyze it, if there is an error, it will indicate the line and you need to repair it to be able to run your program.

The Role of the compiler is to do,

The lexical analysis

It checks all the lexical errors, it means that it checks that every word that you wrote in your source code is correct and belongs to the programming language.

Let’s suppose that there is a compiler for English:

If I say: I’m very happy, this will compile fine.

If I say: I’m very ffkubhjhg a Lexical Error in compilation (only if the word ffkubhjhg exists in English and I don’t know it)

If we take the example of C# language, if we want to show something in the screen we use the predefined method Console.WriteLine(“Hello”); here it compile, if we write Bonsole.WriteLine(“Hello”); it will give a lexical error.

The syntactic analysis

The syntactic error happens in the order of words in a written code.

For example, if we suppose again that there is an English compiler.

If I say: I eat an apple and drink a bottle of water => it compiles fine

Apple eat an I a bottle drink of water => syntactic error.

Same thing if we take the example of printf in C# language, if I say Console.WriteLine()”Hello”; there will be a syntactic error.

The semantic analysis

The compiler ensure that our code will run without problems during execution. So it performs a semantic analysis.

Not all semantic errors are detected by the compiler and they are commonly raised as warning because they are generally errors that happen in execution.

To make it simple, The code that we write must be sensible. It means that even if we write a code using the right keywords and in the right order. It needs to have a right sense

For example, if I say The chicken is giving milk to his baby. It is lexically and syntactically right. But it doesn’t make sense.

Exactly in programming, when you perform a calculation that in some level it tries to divide a number by 0, this will generate problems in the execution.

This is a piece of program that can give an error, again, if you don’t understand it doesn’t matter the section What is General Structure of a program? Will make it clear

int x=0;
int a;
int b=5/x;

=> Semantic error

Code Generation

What we write in a specific language is the source code. The computer doesn’t understand it. So the compiler after verifying that what we wrote is correct, generates a code that is understood by the machine which is called machine code.

Finally we will use the compiler as a tool, here we just explained its role to be aware of them but these roles will be a black box for us.

Editor

We cannot write our source code anywhere. Microsoft word is not the right place to do it.

Here you have two alternatives,

• You can choose a very basic text editor and write your code then in the command line use the compiler. C:\>Compiler MyProgram.c But here you need to be a very patient person. Because this method is not user friendly at all.
• Or we can get a tool that encloses all that we need: compiler, assistance while writing and a very good organization.

Big companies and free software community offer a big variety of editors: Eclipse (free), Visual Studio (Microsoft Licence & Community free version), Visual Code (free), DevCpp (free)…

The editor to choose depends on several parameters like the language, the need ...

What is the General Structure of a program?

The structure of the program may vary according to the environment you use, but here we will define the most standard and basic one.

External uses

In the source code, we can use some pre-defined things. We need to specify the place from which we are importing them.

The first section in the source code is the definition of the external uses of the current file.

Entry point

It is simply the point from which the program starts. The beginning point must be specified in a clear and common way for a program.

It depends also on the kind of the project you create, if you create a console Application in C#, the entry point is a file called program.cs that has a specific main method on it.

Declarative section

Once the entry point is specified, we can start programming. For example, we want to calculate (x*13)+7 for x =1.

We write,

X=1;
Y =(x*13)+7; but what are x and y ?

We need to tell to the program that we will use x and y and they are integer. This is made in the first section of a C# program. And the things that we declare there are called variables. Because we can change then content whenever we want (only for special cases).

Int x;
Int y;  // Declarative section
x=1;
y =(x*13)+7;

Treatment section

It contains all instructions and operations that we want to do. Each operation needs to finish with a ; then the compiler will understand that he is compiling the next instruction.

In all the sections of the program, the programmer can call predefined methods or classes (which are data provided by the framework of programming that you use) or some keywords which are words that exist in the programming language and are automatically understood.

Conclusion

Let's say this is just a very general Idea about what programming is and I really hope that it will help you in your next step of your journey as a programmer.