(Original) An interesting question about the C-language string (C/C ++) (c)

Abstract
This is a younger brother's homework. It is an interesting question about the C-language string.

Introduction
A = 1, B = 2, c = 3... if the input string ABC is used as this type, it indicates 1 + 2 + 3 = 6. If the input string ABCD is used as the input string, it indicates 1 + 2 + 3 + 4 = 10.

C. Yan

1 /*  
2 (C) oomusou 2008 Http://oomusou.cnblogs.com
3
4 Filename: cstring_sum.cpp
5 Compiler: Visual C + + 8.0
6 Description: Demo how to use abstract base class simulate Interface
7 Release: 03/16/2007 1.0
8 */
9 # Include < Stdio. h >
10
11 Void Func ( Char   * S ){
12 Int Sum =   0 ;
13
14 While ( * S)
15 Sum + = ( * S ++   -   96 );
16
17 Printf ( " % D " , Sum );
18 }
19
20 Int Main (){
21 Char S [ 27 ];
22 Scanf ( " % S " , S );
23 Func (s );
24 }

Results

ABC
6

Lines 14 and 15

While ( * S)
Sum + = ( * S ++   -   96 );

Because the C statement string ends with '\ 0', we use while (* s! = '\ 0'), and because C uses the "not 0 is true" feature, it can be omitted as while (* s, it must be difficult to see this method, but in C, this method is an empty comment, there are no questions about "it is not easy to answer 』.

A = 1, B = 2, c = 3... should I make a look-up table for a partition column? A c-character has a special feature: "A character is also equal to its ASCII value", that is, a = 97, B = 98, c = 99, so as long as the ASCII value of each character is 96, it becomes 1, 2, 3.

* S ++, which is also a common method in C programming languages. In the C program language, this parameter is used everywhere. In other words, it refers to the value of s first, after the selection, it refers to the "+ 1" standard. Beginners must not understand this method, but this is already one of the cultures of C.

Conclusion
Although it is a short program, it can be seen that the old team has worked hard for this job, including a lot of negative comments. In the C programming language, while has more opportunities than for, mainly because if the while with pointer can use the * s ++ operator method, while (* s) can be used in the string, which is where c statements are written in other languages.

See also
(Original) How can I print a single character? (C)