1. data type keyword (12)?
(1) char: declare a character variable or function;
(2) double: declare a double-precision variable or function;
(3) enum: declare enumeration type;
(4) float: declare a floating-point variable or function;
(5) int: declare an integer variable or function;
(6) long: declare a long integer variable or function;
(7) short: declare a short integer variable or function;
(8) Signed: declare a signed type variable or function;
(9) struct: declare a structural variable or function;
(10) union: declare * * * object (union) data type;
(1 1) unsigned: declare an unsigned type variable or function;
(12) void: Declare that the function has no return value or no parameters, and declare that it has no type pointer.
Second, the sentence control keywords (12)?
A. circular statement:
1.for: a loop statement;
2.do: the loop body of the loop statement;
3.while: the loop condition of the loop statement;
4.break: jump out of the current loop;
5. Continue: End the current cycle and start the next cycle.
B. conditional statement:
6.if: conditional statement;
7.else: the negative branch of the conditional statement (used with if);
8.goto: unconditional jump statement.
C.switch statement:
9.switch: used to switch statements;
10.case: switch statement branch;
1 1。 Default value: other branches in the switch statement.
D. return statement:
12.return: The subroutine returns a statement (with or without parameters).
Third, the storage type keyword (4)?
1.auto: declare an automatic variable, which is generally not used;
2.extern: the declared variable is being declared in other files (it can also be regarded as a reference variable);
3. Register: declare accumulator variable;
4.static: declare a static variable.
Fourth, other keywords (4)?
1.const: Declare a read-only variable;
2.sizeof: Calculate the length of data type;
3.typedef: used for alias data types (of course, there are other works;
4.volatile: indicates that variables can be changed implicitly during program execution.