Anonymous Struct and Union

The C programming language has anonymous structures and unions, which provide the ability to define structures and unions without specifying a name.

python

python

Since there are no names, direct objects (or variables) are not created from them we use them as nested structures or unions.

You can use anonymous structs/unions when they are nested and will only be used where they are declared.

main


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#include <stdio.h>

struct ASCIItable {
    // Anonymous union
    union {
        char symbol;
        int num;
    };
};

int main()
{
    struct ASCIItable AZtable;
    AZtable.num = 65;

     // number 65 is first symbol `A`,
     // number 97 is last `Z` symbol, hence 97 - 65 = 25, 
     // so 26 iterations required (including number 0)

    for (int i = 0; i < 26; i++)
        printf("x.num = %d | x.symbol = `%c`\n", AZtable.num + i, AZtable.symbol + i);

    return 0;
}

Note

Union allows the same set of bits to be represented differently depending on the context. For example, in an ASCIItable structure, you can interpret the same value as a character (using symbol) or as a numeric value (using num). This can be useful when you need to quickly switch between different data views.

Taak

Swipe to start coding

Create an anonymous structure;
Declare three float fields in it with the names x, y, radius;
Define the fields of the structure instance;
Display the values of the structure fields.

Oplossing

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Sectie 4. Hoofdstuk 3

Anonymous Struct and Union

The C programming language has anonymous structures and unions, which provide the ability to define structures and unions without specifying a name.

python

python

Since there are no names, direct objects (or variables) are not created from them we use them as nested structures or unions.

You can use anonymous structs/unions when they are nested and will only be used where they are declared.

main


              123456789101112131415161718192021222324
            
#include <stdio.h>

struct ASCIItable {
    // Anonymous union
    union {
        char symbol;
        int num;
    };
};

int main()
{
    struct ASCIItable AZtable;
    AZtable.num = 65;

     // number 65 is first symbol `A`,
     // number 97 is last `Z` symbol, hence 97 - 65 = 25, 
     // so 26 iterations required (including number 0)

    for (int i = 0; i < 26; i++)
        printf("x.num = %d | x.symbol = `%c`\n", AZtable.num + i, AZtable.symbol + i);

    return 0;
}

Note

Union allows the same set of bits to be represented differently depending on the context. For example, in an ASCIItable structure, you can interpret the same value as a character (using symbol) or as a numeric value (using num). This can be useful when you need to quickly switch between different data views.

Taak

Swipe to start coding

Create an anonymous structure;
Declare three float fields in it with the names x, y, radius;
Define the fields of the structure instance;
Display the values of the structure fields.

Oplossing

Schakel over naar desktop voor praktijkervaringGa verder vanaf waar je bent met een van de onderstaande opties

Was alles duidelijk?

Bedankt voor je feedback!

Sectie 4. Hoofdstuk 3

Schakel over naar desktop voor praktijkervaringGa verder vanaf waar je bent met een van de onderstaande opties