C和json是非常常用的編程語言，在實(shí)際開發(fā)過程中，經(jīng)常需要進(jìn)行json格式數(shù)據(jù)的解析操作。json數(shù)據(jù)結(jié)構(gòu)相對簡單，但是當(dāng)遇到深度較深、結(jié)構(gòu)比較復(fù)雜的json數(shù)據(jù)時就需要進(jìn)行多層解析。

在多層解析過程中，我們需要根據(jù)json數(shù)據(jù)的結(jié)構(gòu)分層解析。C語言為我們提供了許多操作字符串的函數(shù)，比如strlen、strcpy、strcat等，這些函數(shù)非常適合實(shí)現(xiàn)json的多層解析操作。

//以{"person":{"name":"John","age":30,"array":["apple","banana"]}}為例
char *json_str = "{\"person\":{\"name\":\"John\",\"age\":30,\"array\":[\"apple\",\"banana\"]}}";
char *name, *array1, *array2;
int age;
//第一層解析：獲取person結(jié)構(gòu)體
char *person = strstr(json_str, "\"person\":{");
if (person) {
//第二層解析：獲取name屬性
name = strstr(person, "\"name\":\"");
if (name) {
name += strlen("\"name\":\"");
char *temp = strstr(name, "\"");
int len = temp - name;
strncpy(name, name, len);
name[len] = '\0';
printf("name: %s\n", name);
}
//第二層解析：獲取age屬性
char *age_str = strstr(person, "\"age\":");
if (age_str) {
age_str += strlen("\"age\":");
char *temp = strstr(age_str, ",");
if (!temp) {
temp = strstr(age_str, "}");
}
int len = temp - age_str;
char *temp_str = (char *)malloc(len + 1);
strncpy(temp_str, age_str, len);
temp_str[len] = '\0';
age = atoi(temp_str);
free(temp_str);
printf("age: %d\n", age);
}
//第二層解析：獲取array屬性
char *array_str = strstr(person, "\"array\":[");
if (array_str) {
array_str += strlen("\"array\":[");
char *left = strstr(array_str, "\"");
char *right = strstr(array_str, "\",\"");
right += strlen("\",\"");
char *temp = strstr(right, "\"]");
int len = temp - right;
array1 = (char *)malloc(len + 1);
strncpy(array1, right, len);
array1[len] = '\0';
printf("array1: %s\n", array1);
left = right;
right = strstr(right, "\",\"");
right += strlen("\",\"");
temp = strstr(right, "\"]");
len = temp - right;
array2 = (char *)malloc(len + 1);
strncpy(array2, right, len);
array2[len] = '\0';
printf("array2: %s\n", array2);
}
}

以上代碼就是一個簡單的多層解析例子。在實(shí)際應(yīng)用中需要根據(jù)具體的json數(shù)據(jù)結(jié)構(gòu)來設(shè)計多層解析。