[Signature] at:-2147483648 ~+2147483648.
Unsigned integer [int]: 0 ~ 4294967295.
Short integer short [int]:-32768 ~ 32768.
Unsigned short integer [int]: 0 ~ 65535.
long int:-2 147483648 ~+2 14743648。
Unsigned long integer unsigned [int]: 0 ~ 4294967295.
Character type [signed] char:- 128 ~+ 127.
Unsigned characters: 0 ~ 255.
Single precision floating point: 3.4x 10 (-38) ~? 3.4 times10 (+38).
double: 1.7x 10(-308)~？ 1.7 x 10^(+308)。
long double: 1.7x 10(-308)~？ 1.7 x 10^(+308)。
basic feature
1. High-level language: It is a work unit that combines the basic structure and sentences of high-level language with the practicality of low-level language.
2. Structured language: The notable feature of structured language is the separation of code and data, that is, all parts of the program are independent of each other except the necessary information exchange. This structured way can make the program clear and easy to use, maintain and debug. C language is provided to users in the form of functions, which can be easily called, and there are various loops and conditional statements to control the process of the program, thus making the program completely structured.
4. Cross-platform code level: Due to the existence of standards, almost the same C code can be used in many operating systems, such as Windows, DOS, UNIX, etc. It is also suitable for various models. C language is superior to other high-level languages when hardware operation is needed for writing.
5, the use of pointers: you can directly close to the hardware operation, but C's pointer operation is not protected, which also brings many unsafe factors to it. C++ has made some improvements in this respect, and it has been supported by some users while retaining pointer operation. However, these improvements have increased the complexity of the language, which has also been criticized by other people.
6.java learned the lesson of C++, canceled the pointer operation and some controversial points in the improvement of C++, and achieved good results in terms of security and applicability. However, his own explanation is that running efficiency in virtual machines is not as good as that of C++/C. Generally speaking, C, C++and Java are languages of the same family, occupying the top three in the program usage rankings for a long time.