Shape up notes for Feb 17

const: happen in running
#define: happen at complie time, before program running

const int i = ______ ->have to write a value

const char *p; ---> const
char* const q = name; ---->const, and q points name.

int& foo(int& R)  RENAME, foo(i) = i;

Note about & and |

A - B in C language is equal to A+( ~B + 1 ), so ( ~B + 1 ) + B = 0.

Examples:

#include <cstdio>

using namespace std;

int main(void){

  char A = 0x53;

  char B = 0x9A;

  char C;

  C = A & B;

  printf("%X\n", C);

  C = A | B;

  printf("%X\n", C);

  C = ~A;

  printf("%X\n", C);

  C = ~B;

  printf("%X\n", C);

  C = A + (~A+1); // C = A - A;

  printf("%X\n", C);

  C = A ^ B;

  printf("%X\n", C);

  C = C ^ B;

  printf("%X\n", C);

  printf("Shifts.......\n");

  C = A << 1;

  printf("%X\n", C);

  C = B << 1;

  printf("%X\n", C);

  C = A >> 1;

  printf("%X\n", C);

  C = B >> 1;

  printf("%X\n", C);

  A = 100;

  A = A >> 1;  //  A = A / 2

  printf("%d\n", A);

  A<<=1;  // A *= 2;

  printf("%d\n", A);

  return 0;

}

RESULT:

12

FFFFFFDB

FFFFFFAC

65

0

FFFFFFC9

53

Shifts.......

FFFFFFA6

34

29

FFFFFFCD

50

100

Note: Setbit

#include <iostream>

using namespace std;

char* getBitPattern(unsigned int val, int fromIndex, int toIndex){

  char* bp= new char[toIndex - fromIndex + 2];

  int i, j;

  for(i=toIndex,j=0;i>=fromIndex;i--,j++){

    // slow

    //if((1 << i) & val){

    //  bp[j] = '1';

    //}

    //else{

    //  bp[j] = '0';

    //}

    //fast

    //bp[j] = ((1 << i) & val) ? '1':'0';

    // faster

    bp[j] = !!((1 << i) & val) + '0';

  }

  bp[j] = 0;

  return bp;

}

int main(){

  unsigned int v = 0x0000FF00;

  char* bits = getBitPattern(v, 4, 11);

  cout<<bits<<endl;

  delete[] bits;

  return 0;

}

The rerult of his problem is 11110000.

R0.5 NEED HELP - CCHECK

The problem in my ccheck is that I cannot choose the second option. Whatever I press, the 'X' still hold in the first one.
Here is my code:

CCheck::CCheck(bool Checked,const char* Format, const char* Text, int Row, int Col, int Width, bool IsRadio)
 : CField(Row, Col, Width, 1), Label(Text, 0, 4, (Width-4)){
 Label.frame((CFrame*)this);
 _flag = (int) Checked;
    _radio = (int) IsRadio;
 strcpy(_format, Format);
 _data = &_flag;
}
CCheck::CCheck(const CCheck& C): CField(C), Label(C.Label){
 Label.frame((CFrame*)this);
 _flag = C._flag;
 _radio = C._radio;
 strcpy(_format, C._format);
 _data = &_flag;
}
void CCheck::draw(int fn){
 bio_displayflag(_format, absRow(), absCol(), _flag);
 Label.draw(fn);
}
int CCheck::edit(){
 //eturns bio_flag()'s returned value.
 return bio_flag(_format, absRow(), absCol(), &_flag, _radio);
}
bool CCheck::editable()const{
 //Always return true;
 return true;
}
void CCheck::set(const void* flag){
 _flag = (int) flag;
}
bool CCheck::checked()const{
 return true;
}
void CCheck::checked(bool val){
 _flag = val;
}