Defining an AnsiString matrix in Borland C++ builder without knowing the size -

Defining an AnsiString matrix in Borland C++ builder without knowing the size -

i have next code:

int cl = value1; int fl = value2; ansistring **mat = null; mat = (ansistring **)malloc(sizeof(ansistring)*fl); for(int i=0; < fl; i++) mat[i]=(ansistring *)malloc(sizeof(ansistring)*cl); int count = 0; (int f=0; f<fl; f++){ (int c=0; c<cl; c++){ if (count < str.length()) mat[f][c]=str[++count]; else mat[f][c]='x'; } }

but not working. read several "how to's" can't find right way it.

i'm pretty noob malloc thing advice/help apreciated.

thank much in advance.

never allocate non-pod objects using malloc, are:

mat[i]=(ansistring *)malloc(sizeof(ansistring)*cl)

the constructor of object won't called (you have phone call manually afterwards using placement new operator). line above pleading memory error.

use new[] operator instead:

ansistring **mat = mat = new ansistring*[fl]; for(int i=0; < fl; i++) mat[i] = new ansistring[cl];

you can still access object using mat[m][n], m row number , n column number.

don't forget free memory using delete[] when done:

for(int i=0; < fl; i++) delete[] mat[i]; delete[] mat;

however, using new[]/delete[] still error prone if not careful. recommend utilize std::vector instead, , allow manage of memory you:

std::vector< std::vector<ansistring> > mat( f1 ); for( = 0; < f1; ++i ) mat[i].resize( c1 );

you can still access object using mat[m][n], don't have worry freeing free automatically when goes out of scope.

c++ borland-c++