How to use string.h in c++

Use the string.h header file in C to operate C-style strings, which mainly include the following functions: Copy strings: strcpy(), strncpy() Append strings: strcat(), strncat() Compare characters String: strcmp(), strncmp() Calculate string length: strlen() Initialize memory area: memset()

string.h in C Usage in

string.h is a header file containing functions for manipulating C-style strings. To use it in C, you need to include this header file first:

<code class="cpp">#include <cstring></code>

The following commonly used functions are provided in string.h:

• strcpy(): will The source string is copied into the destination string.
• strncpy(): Copy part of the source string to the target string, the length can be specified.
• strcat(): Append the source string to the end of the target string.
• strncat(): Append part of the source string to the end of the target string, the length can be specified.
• strcmp(): Compares two strings and returns 0 to indicate equality, a positive value indicates that the target string is greater than the source string, and a negative value indicates that the target string is smaller than the source string.
• strncmp(): Compares the partial contents of two strings, the length can be specified.
• strlen(): Calculate the length of the string.
• memset(): Initialize a memory area with a specific value.

Example:

<code class="cpp">#include <cstring>

int main() {
  char str1[] = "Hello";
  char str2[10];

  strcpy(str2, str1);  // 将str1复制到str2
  strcat(str2, " World");  // 追加" World"到str2
  int len = strlen(str2);  // 计算str2的长度

  cout << "str2: " << str2 << endl;
  cout << "Length: " << len << endl;

  return 0;
}</code>

Output:

<code>str2: Hello World
Length: 11</code>

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