Structure of assigning values to an array member in C++

Question

Hello friend,

My code is as follows(In bold-part question):
#include "stdafx.h"
#include <iostream>
using namespace std;;
#define MAX_ARR_SIZE 10
typedef int ElementType;
typedef struct
{
ElementType arr[MAX_ARR_SIZE];
int length;
}MyStr;
void outputE(MyStr *ms){

int i;

for (i = 0; i < ms->length; i++) cout << ms->arr[i] << ",";

cout << ms->arr[i] << endl;

}
int _tmain(int argc, _TCHAR* argv[]){

MyStr ms;

ms.length = MAX_ARR_SIZE;

// try a one-time assignment. but a compiler error has occurred(In addition to each assignment, but are there other ways?).

ms.arr[MAX_ARR_SIZE] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };

outputE(&ms);

system("pause");

return 0;

}
Thanks.

Vulpes · Answer

Unfortunately, you can only use 'list initialization' to initialize local arrays at the same time as they're declared. So this would work: ElementType et[10] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }; and so would this: ElementType et[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }; as the compiler would infer the size of the array to be 10. However, this wouldn't work: ElementType et[10]; et = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }; // not a declaration So you'll need to use a loop to assign values to the struct member, arr: for(int i = 0; i Incidentally, I noticed a mistake in your output() method: void outputE(MyStr *ms){ int i; for (i = 0; i ms->length - 1 ; i++) cout arr[i] cout arr[i] }

Ken H · Answer

Thank you for your explanation,Vulpes :)

Structure of assigning values to an array member in C++

Answers (2)