Section 1 hexadecimal constant variable operators

1. The computer can only recognize code 0.1.

2. Convert n to 10:

   The number of current BITs multiplied by the number of bits in the base number minus the power of 1

3. 10-in conversion to n-in: the method of removing the inverted Remainder

4. One byte represents eight binary digits

5. Byte is the smallest unit in the computer. We usually say that 2 GB of memory means 2 GB of memory.

6. Constant: the amount of value that does not change during the running of the program.

7. Variable: the amount of changes that will occur during the program running

8. A variable represents a storage area. The content stored in the storage area is the value of the variable.

9. Int A = 10;

   Variable type variable name assigned Initial Value

   Naming rules for variable names:

   It consists of numbers, letters, and underscores (_). It cannot start with a number;

   It cannot be the same as the system keyword;

   Known and known;

   In a function, two variables have the same name.

10. % The remainder. 1/2 = 0 is an integer on both sides, and the final result is also an integer.

11. B = ++;

    A = a + 1;

    B =;

12. B = A ++;

    B =;

    A = a + 1;

13. Bitwise operator <, which operates on Binary bits.

    EG-int A = 10, B = 5;

    Int c = A & B;

    1010

    0101

    0000

    Is 1, is 1
    

14. |

    1010

    0101

    1111

    If the same bit is not 0 at the same time, it is not 0
    

15. ^

    1010

    0101

    1111

    The result is 1 if the number of the same digit is different.

16. <>

    1010 <10100 20

    1010> 0101 5

    Move one digit to the left * 2, move one digit to the right/2, and then fill it with zero.

17. The statement is the expression of plus. Each expression has results.

18. Statement is the minimum unit of execution.

19. The formatting output input function defined by the printf scanf system. % d indicates the formatting mark. % u unsigned decimal, % I decimal integer, %. 2f decimal place, retain two decimal places.

20. The data entered in the console is input to the pointer variable.
    

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