qsort – cppreference.com

qsort

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definiert in Header <stdlib.h>
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
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count -
Zahl der Element in dem Array
Original:
number of element in the array
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size -
Größe der einzelnen Elemente in dem Array in Bytes
Original:
size of each element in the array in bytes
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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.

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Rückgabewert

(None)
Original:
(none)
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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 <stdio.h>
#include <stdlib.h>
 
int compare_ints(const void* a, const void* b)
{
    const int *arg1 = a;
    const int *arg2 = b;

    return *arg1 - *arg2;
}
 
int main(void)
{
    int i;
    int ints[] = { -2, 99, 0, -743, 2, 3, 4 };
    int size = sizeof ints / sizeof *ints;
 
    qsort(ints, size, sizeof(int), compare_ints);
 
    for (i = 0; i < size; i++) {
        printf("%d ", ints[i]);
    }

    printf("\n");

    return EXIT_SUCCESS;
}

Output: 

-743 -2 0 2 3 4 99

Siehe auch