通过值传递指针-在函数中分配内存

#include <stdio.h>
#include <stdlib.h>

void allocateMemory(int **ptr, int size) {
    *ptr = (int *)malloc(size * sizeof(int));
    if (*ptr == NULL) {
        fprintf(stderr, "Memory allocation failed\n");
        exit(1);
    }
    for (int i = 0; i < size; i++) {
        (*ptr)[i] = i * 2;
    }
}

int main() {
    int *array;
    int size = 5;

    allocateMemory(&array, size);

    for (int i = 0; i < size; i++) {
        printf("%d ", array[i]);
    }
    printf("\n");

    free(array); // 释放内存
    return 0;
}

free(array);

free(array);
array = NULL;

if (*ptr == NULL) {
    fprintf(stderr, "Memory allocation failed\n");
    exit(1);
}