Question

I have a multipart string like this:

String Y = "part1 part2 part3 part4"; // This is only an example value

I want to write a function that compares the complete string Y with another strin, X. (Normally I will compare it with a list.) If the strings are not equal, then part1 part2 part3 should be compared with X. If they are not equal, X should be compared with part1 part2, and then finally with just part1.

I can use split(" ") to break the string up. I don’t know the number of chunks in the string. How can I write this comparison method?

Answer 1

You can use an algorithm like this:

boolean foundMatch = false;
while(!foundMatch) {
    foundMatch = Y.equals(X);
    if(foundMatch) {
        break;
    }
    else {
        Y = Y.useSplitToRemoveLastPart();
        if(Y.equals("")) {
            break;
        }
    }
}

That’s only pseudocode, of course. It seemed like you had a general idea how to do each of these individual parts. If you need more guidance, just let me know.

EDIT:
Assuming your strings will always be space-delimited like they are in your example, you could do something like this:

String userSplitToRemoveLastPart(String Y) {
    // Find the last space
    int lastSpace = Y.lastIndexOf(" ");

    // Return only the part of the string that comes before the last space
    return Y.substring(0, lastSpace);
}

I haven’t tested this, and it may not be the most efficient way to perform the split, but I think the algorithm is clear.