Problems with output character pointers and string pointers in C and C + +

Let's start by figuring out that there are no strings in C, so there are two forms of string manipulation: You can use a character pointer, or an array of strings ( Here's the pointer variable c, where the system will reallocate memory.)

C Program Example:

1 #include <stdio.h>
2
3 int Main ()
4 {
5 char *a= "Hello";
6 char b[]={' l ', ' I ', ' n ', ' U ', ' X '};
7 Char *c=&b[1];
8
9 printf ("%c\n", *a);
Ten printf ("%s\n", a);
printf ("%s\n", c);
printf ("%s\n", b);
printf ("%c\n", *c);
return 0;
15}

The following results are performed:

[Email protected] ~]$./CP
H
Hello
Inux
Linux
I
4



When you dereference A, the output pointer points to the first character "H", while printf ("%s\n", a) does not output the address of C because it specifies the format of the output string, but rather the string "hello". printf ("%d\n", a) outputs the address of the decimal point C.

Examples of C + + programs:

 1 #include <iostream>
  2 #include <stdio.h
  3 #include <string.h>
  4 using namespace std;
  5
  6 int main ()
  7 {
  8     string s = "string";
  9     String *p=&s;
 10     char * c= "Hello";
 11     cout<<*c<<endl;
 12     cout<< c<<endl;
 13     cout<<s<<endl;
 14     cout<<*p<<endl;
 15     cout<<p<<endl;
 16     return 0;    
 17}
cout output is automatically determined by the format of the output, and there is a string To represent the string, *p the entire string, and p outputs the first address of the string. When COUT<<C is automatically determined as the output string, * C to the first character "H" of the output string when the C is dereferenced.

Execution result: [[email protected] ~]$./test
H
Hello
String
String
0x7fff97664730

Problems with output character pointers and string pointers in C and C + +