2D array init with memset

[stn2007]

#define VECTOR_LENGTH 255
#define MAX_RAD 15
#define MAX_ANGLE 15


double FR[MAX_RAD][MAX_ANGLE];
double FI[MAX_RAD][MAX_ANGLE];


condition a

memset(FR,0x00, sizeof(FR)); //initialization
memset(FI,0x00, sizeof(FI) );

condition b

memset(FR,0x00, sizeof(double) * VECTOR_LENGTH); //initialization
memset(FI,0x00, sizeof(double)* VECTOR_LENGTH );

Can anyone help, why “condition a” is corret, while “condition b” is wrong??

I found out that “condition b” also clear neigbouring variables declared after FR & FI.

[dumparun]

#define VECTOR_LENGTH 255

why is VECTOR_LENGTH 255 .....
15 * 15 = 225
you know the reason for your error, right....