std::qsort – cppreference.com

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definiert in Header `<cstdlib>`

`void qsort( const void ptr, size_t count, size_t size, int (comp)(const void , const void ) );`

Sortiert die angegebene Array, auf das ptr in aufsteigender Reihenfolge. Das Array enthält count Elemente der Größe size. Funktion, auf die comp ist für Objekt Vergleich herangezogen .

Original:

Sorts the given array pointed to by ptr in ascending order. The array contains count elements of size size. Function pointed to by comp is used for object comparison.

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Parameter

ptr	-	Zeiger auf das Array zu sortieren Original: pointer to the array to sort The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
count	-	Zahl der Element in dem Array Original: number of element in the array The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
size	-	Größe der einzelnen Elemente in dem Array in Bytes Original: size of each element in the array in bytes The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
comp	-	comparison function which returns a negative integer value if the first argument is less than the second, a positive integer value if the first argument is greater than the second and zero if the arguments are equal. The signature of the comparison function should be equivalent to the following: `int cmp(const void a, const void b);` The function must not modify the objects passed to it.

Rückgabewert

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Original:

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Notes

Der Typ der Elemente des Arrays muss ein trivial Typ sein, da sonst das Verhalten undefiniert ist .

Original:

The type of the elements of the array must be a trivial type, otherwise the behavior is undefined.

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Beispiel

Der folgende Code sortiert ein Array von Ganzzahlen mit qsort() .

Original:

The following code sorts an array of integers using qsort().

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#include <iostream>
#include <cstdlib>
 
int compare_ints(const void* a, const void* b)   // comparison function
{
    int* arg1 = (int*) a;
    int* arg2 = (int*) b;
    if (*arg1 < *arg2) return -1;
    else if (*arg1 == *arg2) return 0;
    else return 1;
}
 
int main()
{
    int a[] = { -2, 99, 0, -743, 2, 3, 4 };
    int size = 7;
 
    std::qsort(a, size, sizeof(int), compare_ints);
 
    for (int i = 0; i < size; i++) {
        std::cout << a[i] << " ";
    }
    std::cout << '\n';
}

Output:

Siehe auch


bsearch	durchsucht eine Anordnung für ein Element des angegebenen Typ Original: searches an array for an element of unspecified type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Funktion) [edit]

sort	Sortiert einen Bereich in aufsteigender Reihenfolge Original: sorts a range into ascending order The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Funktions-Template) [edit]

is_trivial (C++11)	prüft, ob ein Typ ist trivial Original: checks if a type is trivial The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Klassen-Template) [edit]

C documentation for qsort