01 data type, constant quantity, operator, expression, formatted input and output

In-Process conversion:

1, in order to distinguish the octal, hexadecimal difference: octal before adding 0, hexadecimal x0, such as 058,x059;

2, the conversion of binary, binary, octal, decimal, hexadecimal conversion between. (conversion to binary after the other good conversion)

such as: decimal number 57, binary 111001, from binary to octal system, from the right of the binary to the left 3 digits of a group, the front is not enough to fill 0, that is 111,001, calculated octal 071;

Conversion from binary to 16, from the right of the binary to the left 4 digits of a group, the front is not enough to fill 0, that is 0011,1001, the calculation of hexadecimal as 0x39;

3, Notes

Single-line Comment

/**/Multiple Line comments

4. Basic data type

Commonly used are 3, char, int, float, 1 characters, 4 characters, 4 or 8 characters respectively; placeholder%c,%d,%f

5, variable, representing a storage area

type modifier type name = initial value

eg:int age = ten;

6. Naming rules for variable names

Can only be made up of numbers, words ⺟, underscores, and numbers cannot begin

Cannot have the same name as a system reserved word

Cannot make ⽤ with a duplicate variable name.

⻅ (standard) See name

Hump nomenclature: The first letter in lowercase, the rest of the first letter in uppercase. such as: Studentage

Operator:

7. Note: The expression is a constant, a combination of a variable, an operator, and an expression that returns a value

8, the statement is the smallest unit of program execution, ending with a semicolon

9, input, output statements

scanf () If the Read ⼊ data item type matches the format character, continue reading the ⼊; Otherwise no longer view the remainder, ⽴ is returned

printf (format string, expression 1, expression 2);

A format string consists of a common character and a transformation character.

10, escape character

printf ("\ \ n");

printf ("%%\n");

Escape character

11. Conversion format Control Conversion format control