c语言字符串所有函数(c语言字符串函数有哪些)

Introduction

C programming language is a powerful language that can perform basic programming concepts such as loops, conditional statements, functions, arrays, and pointers. It has a rich set of functions that provides flexibility in the implementation of the program. A string is a sequence of characters that can be represented as an array of characters in the C programming language. In this article, we will discuss the various string functions that are available in C programming language and their application in programming.

String functions in C

String functions are a set of built-in functions that can be used to handle strings in C programming. The following are some of the commonly used string functions in C:

1. strlen() - returns the length of the string
2. strcpy() - copies one string to another
3. strcat() - concatenates two strings
4. strcmp() - compares two strings
5. strchr() - searches for a character in a string
6. strstr() - searches for a substring in a string

These functions are included in the string.h header file in C programming language. In the following sections, we will discuss each of these functions in detail.

Functions Description and Application

1. strlen() - Returns the length of the string. The syntax of the function is:

size_t strlen(const char *str);

Example:
char str[] = "Hello World!";
int len = strlen(str);

2. strcpy() - Copies one string to another. The syntax of the function is:

char *strcpy(char *dest, const char *src);

Example:
char str1[] = "Hello World!";
char str2[20];
strcpy(str2, str1);

3. strcat() - Concatenates two strings. The syntax of the function is:

char *strcat(char *dest, const char *src);

Example:
char str1[20] = "Hello";
char str2[20] = " World!";
strcat(str1, str2);

4. strcmp() - Compares two strings. The syntax of the function is:

int strcmp(const char *str1, const char *str2);

Example:
char str1[] = "Hello";
char str2[] = "Hello";
int cmp = strcmp(str1, str2);

5. strchr() - Searches for a character in a string. The syntax of the function is:

char *strchr(const char *str, int c);

Example:
char str[] = "Hello World!";
char *ptr = strchr(str, 'W');

6. strstr() - Searches for a substring in a string. The syntax of the function is:

char *strstr(const char *haystack, const char *needle);

Example:
char str[] = "Hello World!";
char *ptr = strstr(str, "World");

These string functions can be used in various applications such as searching for a substring in a string, comparing two strings, copying and concatenating strings, and more. They are essential in programming and are widely used in C programming language.