What does include mean?

#include represents the header file containing string processing functions, which is a preprocessing command in C language.

A commonly used header file in the C language standard library, which is needed when using character arrays. The string .h header file defines a variable type, a macro and various functions for operating character arrays.

string.h is widely used in both c language and c language, but the specific situations are not the same. Since traditional C was born out of C, the usage of this term in traditional C is similar to that in C language. In standard C, which has been modified and standardized by the American Standardization Organization, the definition is quite different.

Includes commonly used functions as follows:

strlen finds the length of a string

strcmp compares two strings to see if they are the same

strcat string connection operation

strcpy string copy operation

strncat string connection operation (first n characters)

strncpy string copy operation (first n characters)

strchr query String

strstr Query substring

Examples:

For example, strcat() string link function; strcpy() string copy function, etc.

Take the strcpy function as an example to implement its call:

#include <stdio.h>
#include"string.h" 
int main()
{
char a[50]="asd",b[10]="aaa";
strcpy(a,b);
printf("%s\n",a);
}

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