C - strtok does strange things - c++

Question

i use strtok to split a string into different pieces and assemble them as a struct. This is my code:
object* parseJSON(size_t length, char* json, size_t jsonLen){
char *finalString = prepareJSON(json,jsonLen);
cout << finalString << "\n";
char delimiter[] = ",:";
char *token = strtok(finalString, delimiter);
object *retObj = (struct object *)malloc(length);
size_t returnObjectIndex = 0;
size_t index = 0;
bool firstTime = true;
struct object item;
while(token != NULL){
if((index % 2) != 0){
if(firstTime){
item.Type = token;
firstTime = false;
} else {
item.ID = token;
retObj[returnObjectIndex] = item;
returnObjectIndex++;
firstTime = true;
}
}
token = strtok(NULL,delimiter);
index++;
}
return retObj;
}
This is the finalString:
Type:temp,id:3,Type:temp,id:1
In my mind this should come out with this code:
for(int n = 0; n < 5; n++){
cout << returnObject[n].Type << " " << returnObject[n].ID << "\n";
}
as:
temp 3
temp 1
but instead i get this on the console:
temp 3
temp 1
h"° Ó*°
C
Is this because i loop 5 times even though there should be only 2 elements in the array? I loop 5 times because i can't get the number of elements of the array in the pointer (atleast i think that this is not possible).
Any help is very much appreciated
Best regards
Edit: This is my prepareJSON function:
char* prepareJSON(char* json, size_t jsonLen){
char forbiddenChars[] = {'[', '{','\"', '}', ']'};
bool isForbbidenChar = false;
char* finalString = (char*)malloc(jsonLen);
size_t finalStringIndex = 0;
for(size_t i = 0; i < jsonLen; i++){
char c = json[i];
isForbbidenChar = false;
for(int k = 0; k < 5; k++){
if(c == forbiddenChars[k]){
isForbbidenChar = true;
break;
}
}
if(isForbbidenChar){
continue;
}
else{
finalString[finalStringIndex] = c;
finalStringIndex++;
}
}
return finalString;
}
and this my main function:
int main(){
object *returnObject;
char json[] = "[{\"Type\":\"temp\",\"id\":\"3\"},{\"Type\":\"temp\",\"id\":\"1\"}]";
returnObject = parseJSON(5,json, strlen(json));
for(int n = 0; n < 5; n++){
cout << returnObject[n].Type << " " << returnObject[n].ID << "\n";
}
}
Solution:
I did indeed allocate too little memory, changed it:
object *retObj = (struct object *)malloc(sizeof(struct object) * length);
Now it works!