The role of strcmp in c language

strcmp function compares two strings and returns an integer value: 0 (equal), positive number (the first string is greater than the second string), negative number (the first string is less than the second string) string).

The role of strcmp in C language

The strcmp function is a function in the C standard library, used for comparison Two C strings. It receives two strings as parameters and returns an integer value representing the comparison result.

Explanation of return value:

• 0: If the two strings are the same.
• Positive number: If the first string is alphabetically larger than the second string (that is, the ASCII code value of the first string is greater).
• Negative number: If the first string is lexically smaller than the second string (that is, the ASCII code value of the first string is smaller).

Working principle:

The strcmp function compares characters in two strings one by one. If a non-matching character is encountered, the difference in ASCII codes of the first non-matching character is returned. If the two strings are the same, the function compares all characters and returns 0.

Syntax:

<code class="c">int strcmp(const char *str1, const char *str2);</code>

Parameters:

• str1: The number to be compared a string.
• str2: The second string to compare.

Example:

<code class="c">#include <stdio.h>
#include <string.h>

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

  int result = strcmp(str1, str2);

  if (result == 0) {
    printf("字符串相同。\n");
  } else if (result > 0) {
    printf("第一个字符串大于第二个字符串。\n");
  } else {
    printf("第一个字符串小于第二个字符串。\n");
  }

  return 0;
}</code>

Output:

<code>第一个字符串小于第二个字符串。</code>

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