32 keywords in C Language

The so-called keyword is also called a reserved word. It is a type of identifier. The standard stipulates that it is the default type of the compiler. Therefore, users cannot use its same identifier to represent other things. Standard C has 32 keywords: one data type keyword 12: 1. char 2. short 3. int 4. long 5. enum 6. float 7. double 8. signed 9. unsigned 10. struct 11. union 12. void two control type keywords 12 loop statements 1.for 2.do 3. while 4. break 5. continue Condition Statement 6.if 7. else 8. goto switch statement 9. switch 10. case 11. default return statement 12. return three Storage types 4 1. auto // declare automatic variables, which are generally not used. Local variables are auto type 2 by default. static // declare static variables 3. extern // declare an external variable 4. register // declare register variable 4 other keywords 4 1. const // Declare Read-Only variables 2. sizeof // operator, memory occupied by computing data 3. typedef // custom type 4. volatile // The modified variables may change. Do not use define and include as keywords. They are only precompiled pseudo commands .. The C99 standard adds five more keywords, namely, restrict, which can only be used to restrict and constrain pointers. It also indicates that pointers are the only and initial inline restrained functions for accessing a data object, in C ++, It is a macro-defined optimization implementation method _ Bool unsigned int type, which is defined as Boolean in C99, only two values_1 and two values_complex Complex classes _ Imaginary pure virtual number type C11 standard added a keyword _ Generic type on the basis of C99