Course C Initial – 3rd Variables Part. 1

Lesson 3 Part. 1.
Hello again! As promised in the previous class, now I speak about variables in C language.
First, what’s a variable? The answer is important because it will help us to learn more and use them.
Definition: capable of being varied or changed; alterable. (source: www.dictionary.com).
That’s the definition that we need!
So, there’s some variables types in C language. They’re:
  • Global;
  • Locale;
  • Constant;
  • Volatile;
Inside each one of those cases, we have in resume, 4 type that can be represent in each or all those cases. Below, you’ll can see its names.
  • char – ‘a’, ‘b’, ‘c’,...;
  • int – 1, 2, 4, 7,...;
  • float – 7.553279, 8.856347,...;
  • double – 9.5896324789632, 10.5885569347799,...;
There’s variations inside each format, but we’ll see in the future. How we can see above, the type data that the variables types represent. Char is for character data, int is for integer, float is for floating point and double is a long floating, for greater or smaller numbers.
With this, we have the enough to declare a variable, show below:

So, now we learned to declare variables in C language. But I have a NOTE: Caution is need when you want use GLOBAL Variables, this type is declared outside the functions in C and all code knows it and if it wasn’t a constant, it can be changed and many times, this is unpredictable.
Now, what the variables make? It reserves memory space. For help you, read this Article. This space is where is the data in memory, but when we’re programming, we unknown where the data is in the memory, we works with variables.
In the next lesson, we’ll see the second part of this theme. Well, that’s all folks!
See you later!

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