Hello,
If i have this code
this code return a access violation, so what can i do for the changes in function init on variable matrix can be aply on main function?Code:void init( char ** matrix) { matriz = new char*[5]; for(int i = 0 ; i < linhas; i++) matriz[i] = new char[5]; for(int i = 0; i < 5; i++) for(int j = 0 ; j <5; j++) matriz[i][j] = 'm'; } int main() { char **matrix; init(matrix); cout << matrix[0][0]; }
sorry about my english
[]
i forgot to change variable linhas, in his place must be a 5.
Assuming the matriz variable is actually a mistype of matrix, I would say the problem is:
This line doesn't change your original value of matrix in main. You need to do one of two things:Code:matriz = new char*[5];
Option 1: Return the pointer to your matrix as a result
Option 2: Use another indirection level.Code:char **init(void) { char ** matrix; ... return matrix; } int main() { char **matrix = init(); ... }
Code:void init( char *** matrix) { *matrix = new char*[5]; for(int i = 0 ; i < 5; i++) (*matrix)[i] = new char[5]; for(int i = 0; i < 5; i++) for(int j = 0 ; j <5; j++) (*matrix)[i][j] = 'm'; } int main() { char **matrix; init(&matrix); ... }
Compilers can produce warnings - make the compiler programmers happy: Use them!
Please don't PM me for help - and no, I don't do help over instant messengers.
Where do matriz and linhas come from?
Look up a C++ Reference and learn How To Ask Questions The Smart WayOriginally Posted by Bjarne Stroustrup (2000-10-14)
> matriz = new char*[5];
But your parameter is matrix
In order to change the variable in main, you need to pass a reference to it, like so.
void init( char ** &matrix)
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
thanks for help.. Salem ideia works weel =)
for laserlight the matriz is matrix, i make a mistake when i did some changes on code, and linhas i explain in top that in it place must be a 5
