Non-void function does not return a value in all control paths in recursive function in C-CodePudding

I am trying to make a recursive function where I am returned true if a string includes a comma. However, I am getting the following error: Non-void function does not return a value in all control paths

This is my code:

bool hasComma(string sentence, int index) {
    if (index == -1)
        return false;
    else if (sentence[index] == ',')
        return true;
    else
        hasComma(sentence, index - 1);
        
}

int main() {
    string sentence = "Hello, world.";
    if (hasComma(sentence, int(sentence.size() - 1)))
       cout << "Sentence has a comma." << endl;
    
    return 0;
}

Any help would be appreciated.

CodePudding user response：

This:

else
    hasComma(sentence, index - 1);

Should be:

else
    return hasComma(sentence, index - 1);

Otherwise, what are you returning? That's what the compiler is warning you about.

CodePudding user response：

At the point you're making the recursive call, you're not returning anything. You want to return the result of that call.

bool hasComma(string sentence, int index) {
    if (index == -1)
        return false;
    else if (sentence[index] == ',')
        return true;
    else
        return hasComma(sentence, index - 1);
}