CS225 Day 12 Notes

main.c

//Day 12 C routines  
  
#include <stdio.h>
  
void routineA();  
void routineB();  
void routineC();  
void routineD();  
  
int main()  
{  
    printf("\n---------\nRoutine A\n---------\n");
    routineA();  
  
    printf("\n---------\nRoutine B\n---------\n");  
    routineB();  
  
    printf("\n---------\nRoutine C\n---------\n");  
    routineC();  
  
    printf("\n---------\nRoutine D\n---------\n");  
    routineD();  
}  

#include "routineA.c"
#include "routineB.c"
#include "routineC.c"
#include "routineD.c"

routineA.c

// - - - - - - - - - - - - - - - - -  
// Routine A, Sizes of C integers  
// - - - - - - - - - - - - - - - - -  
// climits (cf. cs131 textbook (Hennefeld, Baker, Burchard) p. 51)  
//  defines constants LONG_MAX, LONG_MIN,   
//  INT_MAX, INT_MIN, SHRT_MAX, SHRT_MIN, CHAR_MAX, CHAR_MIN  
//  and the same for unsigned, ULONG_MAX, etc. (No MIN's for unsigned. Why not?)  
//  sizeof is a built in function that tells the storage space size of any variable or constant.  
#include <limits.h>  
  
void routineA()  
{  
    printf("Min. char: %d\n", CHAR_MIN);
    printf("Min. long: %ld\n", LONG_MIN);
    printf("Max. long: %ld\n", LONG_MAX);

    long a = 66;  
    printf("a(long) contains %ld\n", a);
    printf("%ld byte(s)\n", sizeof a);
    printf("long is %ld bytes\n", sizeof(long));
}

routineB.c

// - - - - - - - - - - - - - - - - -  
//Routine B, Investigate unsigned integers in C, with some alternative number entries  
// - - - - - - - - - - - - - - - - -  
  
void routineB()  
{  
    int i = -1; // int is signed.  
    //Other integer types are short, long.  
    printf("%d\n", i);
    unsigned int u;  
    //u will be the biggest unsigned value, 1 less than the # of possibles.  
    u = i; // type "casting" takes place here, without notice  
    printf("%u biggest unsigned INT\n", u); 
    //The u is for unsigned. See http://www.cplusplus.com/reference/clibrary/cstdio/printf/
    unsigned int v;  
    v = 0xFFFF; // zero 0x marks hex input   
    printf("%u=%x hex\n", v, v); 
    //The x is for hex output. See http://www.cplusplus.com/reference/clibrary/cstdio/printf/
    unsigned int w;   
    w = 65536;  
    printf("%u squared = %u\n", w, w*w);
}

routineC.c

// - - - - - - - - - - - - - - - - -  
//Routine C, Powers of 129  
// - - - - - - - - - - - - - - - - -  
  
void routineC()  
{  
      
    int i = 1; // int (without modifiers) is signed.    
    unsigned int u;  
    u = 1;  

    printf("%d is signed \t %u is unsigned \n", i, u);
      
    for (int loop =1; loop <=20; loop++)  
    {  
    i=i*129;  
    u=u*129;  
    printf("%d is signed \t %u is unsigned \n", i, u);
    }  
}

routineD.c

// - - - - - - - - - - - - - - - - -  
//Routine D . Using C bitwise & logical operations  
// - - - - - - - - - - - - - - - - -  
  
void routineD()  
{  
    short numA=1, numB=3, numC, numD; // 0000 0001, 0000 0011  
      
    printf("%d\t%d\n", numA, numB);
    // Example of the bitwise-AND operator &  
    numC = numA & numB; // numC is now 1  
    numD = numA && numB; // this shouldn't be legal, Logical op  
    printf("%d\t%d\n", numC, numD);
      
    // bitwise OR (inclusive) |  
    numC = numA | numB; // numC is now 3  
    numD = numA || numB; // this shouldn't be legal, Logical op  
    printf("%d\t%d\n", numC, numD);
    // bitwise OR (exclusive) ^  
    numC = numA ^ numB; // numC is now 2  
    printf("%d\n", numC);
      
    // bitwise NOT (1's complement) ~  
    numC = ~numB; // numC is now -4, 1111 1100  
    numD = !numB; // numC is Logical Not of 0000 0011. What?  
    printf("%d\t%d\n", numC, numD);
}