Question

Just stuck on c syntax regarding strings.

Say I have a string like (name[5]="peter";) in c say if I just wanted to print the last character of string or check the last character of the string, which in this case would be 'r' how can I do this?

The way I was thinking does not seem to work

name[5]="peter";
if(name[5]=="r") printf("last character of name is r");

Question: is there some sort of function to do this that can check one character of array, is a certain value, like name[5] is ‘r’ in string peter or likewise name[1] is ‘n’

Also how do I use printf to print that certain char, having problems using

printf("last character of name is %s",name[5]) ???

Thanks

Answer 1

First thing, strings are null-terminated. For a five-character string you need to allocate a 6-character array to handle the '\0' character at the end of the string.

char name[6] = "peter";
// peter is {'p', 'e', 't', 'e', 'r', '\0'}

To check what individual characters are, index the string using square brackets. The first character is index 0, the second is index 1, etc. Also, C makes a distinction between strings and individual characters. A string is written with "double quotes". Characters are written with single quotes: 'r'.

if (name[4] == 'r') {
    printf("fifth character of name is r\n");
}

To find the last character you need to know the length of the string. If you know the length ahead of time you can hard code it; otherwise, use the strlen function to calculate the string length. And then subtract 1 because indexes are 0-based.

if (name[strlen(name) - 1] == 'r') {
    printf("last  character of name is r\n");
}

To print individual characters with printf you can use the %c format specifier. %c prints a single character.

printf("fifth character of name is %c\n", name[4]);
printf("last  character of name is %c\n", name[strlen(name) - 1]);