c - 重新分配内存并在 C 中重新分配的内存空间添加一个字符串

Question

我在动态分配的字符串数组末尾添加“记录”时遇到问题。在为要添加的记录重新分配更多内存之前，一切正常，然后我基本上复制了我最初所做的，但现在使用了 realloc。在我输入完添加的记录后，出现错误，我不知道如何添加记录。注意* 构成的代码实际上是从原始代码中剥离出来的。我已经尝试了很多方法但都无济于事，感谢您提前提供的所有帮助。

#include <stdio.h>
#include <stdlib.h>
#define STRINGSIZE 21

void addRecords( char **Names, int classSize);

int main(){
    char **Names;
    int classSize, i;

    //User will be able to choose how many records he woudld like to input.
    printf("Please indicate number of records you want to enter:\n");
    scanf("%d", &classSize);

    Names=malloc(classSize*sizeof(char*));

    for (i=0; i<classSize; i++) {
        Names[i]=malloc(STRINGSIZE*sizeof(char));
    }
    printf("Please input records of students (enter a new line after each record), with following format: first name....\n");

    for (i=0; i<classSize; i++) {
        scanf("%s", *(Names + i));
    }

    for (i=0; i<classSize; i++) {
        printf("%s ", *(Names+i));                
        printf("\n\n");
    }

addRecords(Names, classSize);
}

void addRecords(char **Names, int classSize){
    int addition, i;

    printf("How many records would you like to add?\n");
    scanf("%d", &addition);

    Names=realloc(Names, (classSize+addition)*sizeof(char*));

    for (i=classSize; i<(classSize+addition); i++) {
        Names[i]=malloc(STRINGSIZE*sizeof(char));
    }

    printf("Please input records of students (enter a new line after each record), with followingformat: first name....\n");

    for (i=classSize; i<classSize+addition; i++) {
        scanf("%s", *(Names + (classSize + i)));
    }
    printf("\n\n");
    for (i=0; i<classSize+addition; i++) {
        printf("%s ", *(Names+i));
    }

    printf("\n\n");
}

Answer 1

你正在写出数组的边界:

for (i=classSize; i<classSize+addition; i++) {
    scanf("%s", *(Names + (classSize + i)));

改为

for (i=classSize; i<classSize+addition; i++) {
    scanf("%s", *(Names + i));

请注意 Names[i] 比 *(Names + i) 更具可读性>