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I have a question about this: **ptr

I can see all other (ptr++, &ptr, *ptr)

I do not know what will be the best way to see how it works **ptr (Pointed from the dotted.)

Thank you to anyone who can clarify this is doubtful.

The important part of understanding this is to understand how pointers work.

Let’s imagine that we declare a pointer with the ABC content:
    const char * c=”ABC”;

Then “ABC” is somewhere in memory and the pointer is also in memory. If we want to create a pointer to c, it is also possible with the code:

const char **cp = &c;

In this case the cp pointer is also allocated in memory and is pointing to where pointer c is.

For example, if we look at a piece of memory:

Endereço
21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30
-----------------------------------------------
 A |  B |  C |    | 21 |    | 25 |    |    |
Conteúdo

cp está no endereço 27 e aponta para o endereço 25.
c está no endereço 25 e aponta para o endereço 21.
no endereço 21, temos a string ABC.

Imagine you have multiple text pointers

char *lang_pt[] = {"rato", "teclado", "monitor"};
char *lang_en[] = {"mouse", "keyboard", "screen"};

and you want to make a single pointer that points to the language the user chose

char **lang_user;
if (rand() % 2) lang_user = lang_pt;
else            lang_user = lang_en;

printf("2. %sn", lang_user[1]); // teclado???? keyboard???

Quoting Stack Overflow:

• list of characters (one word): char * word;
• sentence (a list of words): char ** sentence;
• monologue (list of phrases): char *** monologue;

And so on …

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