expected primary-expression before ‘]’

This error message typically occurs when there is a syntax error in the code, specifically involving an array. The compiler is expecting a valid expression before the closing bracket ']', but it is not finding one.

To fix this error, check the syntax of the code where the error occurred. Make sure that you have declared the array properly, and that the index used to access the array is within its bounds. Also, ensure that there are no missing or extra symbols or characters in the code.

Here's an example of incorrect syntax that could result in this error:

int myArray[5];
myArray[5];

In this case, the array myArray has 5 elements, but the index used to access the array is outside its bounds. To fix the error, change the index to a valid value:

int myArray[5];
myArray[4];