primary-expression before ']' error meaning

Question

I am trying to fix a code with errors, and I have one more error left I cannot figure out. The error says: expected primary-expression before ']' token, what does this mean? I have checked for misplaced semicolons and variable names, but cannot find anything. Here is my code(I have commented the line with an error):

// countOnes.cpp
#include<iostream>
#include<cstdlib>
using namespace std;
void countOnes( int array[] ); // Count the number of 1s in a given int array.
const int arraySize = 10;
int array[ arraySize ];
int countOne = 0;
int main()
{
 for ( int i = 0; i <= arraySize; i++ )
 {
 array[ i ] = rand() % 3; // Fill array with 0, 1 or 2 randomly
 cout << array[ i ] << " ";
 }
 countOnes( array[], arraySize ); //ERROR
 cout << "\n The number of 1s in the array: " << countOne;
 return 0;
}
void countOnes( int array[], int arraySize )
{
 for ( int i = 0; i <= arraySize; i++ )
 if ( array[ i ] == 1 )
 countOne = countOne + 1;
 return;
}

• balki: You should consider using std::vector in c++
• balki: Its not an runtime-error, its a compiler-error

Answer 1

No square brackets needed.

countOnes(array(削除) [] (削除ここまで), arraySize);

Answer 2

countOnes( array[], arraySize ); //ERROR

You don't need [] here
Also declaration of

void countOnes( int array[] ); // Count the number of 1s in a given int array.

Doesn't correspond to its definition

void countOnes( int array[], int arraySize )

• alexrider: @user2085224 I can ask the same way why would you do? When you declare function, you declare it in a way that it will accept array as 1st param. And when you call it compiler already knows that array is indeed of type array(not so good name for an variable btw). Thus no additional hints required. Or did you mean something else when putting []?

Answer 3

'array' is treated as reserved word in Microsoft's extension of C. See Why is "array" marked as a reserved word in Visual-C++?. Replace 'array' by something else, e.g. 'arr'.

• Pete Becker: That thread, despite its name, does not establish that Microsoft's compiler treats array as a reserved word in C or C++. It's about the syntax highlighter. Treating array as a reserved word would violate the language definition.

Answer 4

If you want to pass an array, you can pass a pointer to the first element to the array:

 void countOnes( int* array, int size );