In plain C, when initializing a matrix you can do it:
int m[2][2] = { {2,3} , {3,4} };
but I am trying to do it at run time:
And I get compiling errors. It looks like this way is not allowed.Code:int F[5][8]; int main() { int x= 1; F[x] = {-6, -3, 0, 4, 8, 6, 2, -4 }; int x= 2; F[x] = {-7, -3, 0, 5, 8, 6, 2, -8 }; ..... return 0; }
Is there any way to inialize a matriz in bulk, so that there is no need to initialize values one by one.
thanks
int m[2][2] = { {2,3} , {3,4} };
It's already initialization in bulk.
That is not what I want. suppose I want to initialize it depending on a var:Originally Posted by Bayint Naung
I can not do this also. any idea or I must do it value by value?Code:int F[5][8]; int main() { if (z == 18) { F[1] = {-6, -3, 0, 4, 8, 6, 2, -4 }; } else { F[1] = {-7, -3, 0, 5, 8, 6, 2, -8 }; } ..... return 0; }
Or use variadic macro. Example (Not suppose to be perfectCode:if (z == 18) { int temp[] = {-6, -3, 0, 4, 8, 6, 2, -4 }; /* of course you can use #define INIT_ARRAY { -6, -3,0,blah} int temp[] = INIT_ARRAY; */ // copy memcpy(f[1],temp,sizeof(temp)); } else { int temp[] = {-7, -3, 0, 5, 8, 6, 2, -8 }; // similar }
Code:#define INIT_ARRAY(array,type,...) \ do { \ memcpy(array, ( type [ sizeof(array)/sizeof(array[0]) ]) { __VA_ARGS__ }, sizeof(array) ); \ } while(0) INIT_ARRAY(f[1],int, 3,4,5 ); // eg usage } while(0)
Last edited by Bayint Naung; 06-23-2010 at 03:19 AM.
macro? memcpy? stay away
just make a new array and copy over the contents
just some general advice:Code:if (z == 18) { int temp[] = {-6, -3, 0, 4, 8, 6, 2, -4 }; for(...) { F[1][i] = temp[i] } } else {
when writing a program, the first thing you should do is get something that works and is correct. then go back and do whatever you feel is required. i think you knew exactly how to get around this problem by using a temp array and i dont think you should have spent any more than a few seconds trying to think of better method. the temp array solution was simple, obvious and clear.
its like when you are writing an essay at home. the first thing you should do is write it all out. then you should go and choose fonts, choose header styles, colors, pictures, etc. but only after youve finished
and use spaces, not tabs. if you must use tabs, then dont mix and match with spaces.
