C-language string processing functions

C-language string processing functions

Introduction to string processing functions in C Language

The following describes eight basic common string processing functions, which are often used in numeric arrays (some functions ). These functions are generally provided in all C language compiling systems.

1,Puts Function-- Output string functions

The general format is puts (string group)

Purpose: Output a string to the terminal. For example, char is a string and the initial value is assigned. Call puts (string); to output the string.

2,Gets Function-- Input string Function

General Format: gets (character array)

Purpose: input a string to the character array from the terminal and obtain a function value to become the starting address of the character array.

Gets (str );

Keyboard Input, you know.

Note: The puts and gets functions can only output or input one string.

3,Strcat Functions-- String connection Function

General Format: strcat (character array 1, character array 2 );

Purpose: connect the strings in two string arrays and connect string 2 to the end of string 1.

Note: The character array 1 must be large enough to accommodate the connected New String.

4,Strcpy/strncpy Function-- String copy Function

General Format: strcpy (character array 1, string 2 );

Purpose: Copy string 2 to character array 1.

For example, char str1 [10], str2 [] = "DongTeng ";

Strcpy (str1, str2 );

The execution result is: you understand

Note: 1. You cannot directly assign a String constant or character array to a character array using a value assignment statement.

2. Use strncpy to assign values to characters at the specified position. Strncpy (str1, str2, 3); copies the 3rd characters in str2 to str1.

5,Strcmp Functions-- String comparison Function

General Format: strcmp (string 1, string 2 );

Purpose: Compare the differences between two strings. There are different comparison rules.

6,Strlen Function-- Test the function of String Length.

General Format: strlen (character array );

For example, char str [10] = "DongTeng ";

Printf ("% d", strlen (str ));

The result is as follows: 5

7,Strlwr Function-- Converts the string to lowercase.

General Format: strlwr (string );

8,Strupr Function-- Convert to an upper-case Function

General Format: strupr (string ).

The above is just a simple common function in C language. I hope you can correct the shortcomings.