The library function used to find the last occurrence of a character in a string is

The library function used to find the last occurrence of a character in a string is strrchr() in C language. Here is how you can use it:

1. Include the string library in your program using #include <string.h>.

2. Declare your string and the character you want to find. For example: char str[] = "Hello, World!"; char ch = 'o';.

3. Use the strrchr() function to find the last occurrence of the character. For example: char *res = strrchr(str, ch);.

4. The function will return a pointer to the last occurrence of the character in the string. If the character is not found, the function returns a null pointer.

5. You can print the result using printf(). If the result is not null, print the string from the found character to the end. If the result is null, print a message saying the character was not found. For example:

if (res != NULL)
    printf("The character '%c' is found and the last occurrence is '%s'\n", ch, res);
else
    printf("The character '%c' is not found\n", ch);

This will print: The character 'o' is found and the last occurrence is 'orld!'.