Chapter 2

  1. Binary to hexadecimal
    1. 0100 0101 0110 0111 = 4567
    2. 1000 1001 1010 1011 = 89ab
    3. 1111 1110 1101 1100 = fedc
    4. 0000 0010 0101 0010 = 0252
  2. Hexadecimal to binary
    1. 83af = 1000 0011 1010 1111
    2. 9001 = 1001 0000 0000 0001
    3. aaaa = 1010 1010 1010 1010
    4. 5555 = 0101 0101 0101 0101
  3. Number of bits
    1. ffffffff, 32 bits
    2. 7fff58b7def0, 48 bit
    3. 1111 in binary is 4 bits
    4. 1111 in hexadecimal is 16 bits
  4. Number of hexadecimal digits
    1. 8 bits, 2 hex digits
    2. 32 bits, 8 hex digits
    3. 64 bits, 16 hex digits
    4. 10 bits, 3 hex digits
    5. 20 bits, 5 hex digits
    6. 7 bits, 2 hex digits
  5. r = 10, n = 8, d7 = 2, d6 = 9, d5 = 4, d4 = 5, d3 = 8, d2 = 2, d1 = 5, d0 = 4 and r = 16, n = 8, d7 = 2, d6 = 9, d5 = 4, d4 = 5, d3 = 8, d2 = 2, d1 = 5, d0 = 4
  6. Binary to decimal
    1. 1010 1010 = 170
    2. 0101 0101 = 85
    3. 1111 0000 = 240
    4. 0000 1111 = 15
    5. 1000 0000 = 128
    6. 0110 0011 = 99
    7. 0111 1011 = 123
    8. 1111 1111 = 255
  7. Binary to decimal
    1. 1010 1011 1100 1101 = 43981
    2. 0001 0011 0011 0100 = 4916
    3. 1111 1110 1101 1100 = 65244
    4. 0000 0111 1101 1111 = 2015
    5. 1000 0000 0000 0000 = 32768
    6. 0000 0100 0000 0000 = 1024
    7. 0111 1011 1010 1010 = 31658
    8. 0011 0000 0011 1001 = 12345
  8. Hexadecimal to decimal
    1. a000 = 40960
    2. ffff = 65535
    3. 0400 = 1024
    4. 1111 = 4369
    5. 8888 = 34952
    6. 0190 = 400
    7. abcd = 43981
    8. 5555 = 21845
  9. Unsigned decimal to hexadecimal
    1. 100 = 64
    2. 123 = 7b
    3. 10 = 0a
    4. 88 = 58
    5. 255 = ff
    6. 16 = 10
    7. 32 = 20
    8. 128 = 80
  10. Unsigned decimal to hexadecimal
    1. 1024 = 0400
    2. 1000 = 03e8
    3. 32768 = 8000
    4. 32767 = 7fff
    5. 256 = 0100
    6. 65535 = ffff
    7. 4660 = 1234
    8. 43981 = abcd

  11. Since there are 12 values, we need 4 bits.

    grade code grade code
    A 0x0 C 0x6
    A- 0x1 C- 0x7
    B+ 0x2 D+ 0x8
    B 0x3 D 0x9
    B- 0x4 D- 0xa
    C+ 0x5 F 0xb

  12. Lowercase

    char code char code char code char code char code
    a 0x61 g 0x67 m 0x6d s 0x73 y 0x79
    b 0x62 h 0x68 n 0x6e t 0x74 z 0x7a
    c 0x63 i 0x69 o 0x6f u 0x75    
    d 0x64 j 0x6a p 0x70 v 0x76    
    e 0x65 k 0x6b q 0x71 w 0x77    
    f 0x66 l 0x6c r 0x72 x 0x78    

  13. Uppercase

    char code char code char code char code char code
    A 0x41 G 0x47 M 0x4d S 0x53 Y 0x59
    B 0x42 H 0x48 N 0x4e T 0x54 Z 0x5a
    C 0x43 I 0x49 O 0x4f U 0x55    
    D 0x44 J 0x4a P 0x50 V 0x56    
    E 0x45 K 0x4b Q 0x51 W 0x57    
    F 0x46 L 0x4c R 0x52 X 0x58    

  14. Punctuation

    char code char code char code char code char code
    spc 0x20 ’ 0x27 . 0x2e ? 0x3f ` 0x60
    ! 0x21 ( 0x28 / 0x2f @ 0x40 { 0x7b
    ” 0x22 ) 0x29 : 0x3a [ 0x5b } 0x7c
    # 0x23 * 0x2a ; 0x3b \ 0x5c | 0x7d
    $ 0x24 + 0x2b < 0x3c ] 0x5d ~ 0x7e
    % 0x25 , 0x2c = 0x3d ^ 0x5e    
    & 0x26 - 0x2d > 0x3e _ 0x5f    
  15. dec2Hex 
    // Convert from decimal to hexadecimal

#include <stdio.h>

int main(void)
{
    unsigned int value;

    printf("Decimal: ");
    scanf("%u", &value);
    printf("%u = 0x%02x\n", value, value);

    return 0;
}
  16. hex2Dec.c 
    // Convert from hexadecimal to decimal

#include <stdio.h>

int main(void)
{
    unsigned int value;

    printf("Hexadecimal: ");
    scanf("%x", &value);
    printf("0x%02x = %u\n", value, value);

    return 0;
}
  17. The integer is -1, and the string is 0xffffffff.