Detecting First Letter Match in C++ String with Substr Function

[ineedhelpnow]

Write an expression to detect that the first character of userInput matches firstLetter.

Sample program:

#include <iostream>
#include <string> 
using namespace std;

int main() {
   string userInput;
   char firstLetter = '-';

   userInput = "banana";
   firstLetter = 'b';

   if (<STUDENT CODE>) { 
      cout << "Found match: " << firstLetter << endl;
   }
   else {
      cout << "No match: " << firstLetter << endl;
   }

   return 0;
}

i tried userInput.find(firstLetter, 1) but it only partially passed

 

[MarkFL]

Okay, we know the [m]str.substr(pos,len)[/m] method in C++ will return from the string [m]str[/m], the sub-string beginning at position [m]pos[/m] and spanning length [m]len[/m].

So, we want to see if the first character of the string [m]userInput[/m] matches the value of [m]firstLetter[/m].

First, what values of [m]pos[/m] and [m]len[/m] do we want?

 

[ineedhelpnow]

um Mark...are you sure this is c++ you're talking about? (Blush) I've never heard of those commands before.

 

[MarkFL]

um Mark...are you sure this is c++ you're talking about? (Blush) I've never heard of those commands before.

You told me that you are familiar with the [m]substr()[/m] function. You will replace [m]str[/m] with [m]userInput[/m] since this is the name of the string from which you wish to extract the first character. I was just giving you the general usage. You will also need to determine what values you need for the parameters [m]pos[/m] and [m]len[/m].

 

[ineedhelpnow]

ive never heard of pos and lens before i meant.

 

[MarkFL]

ive never heard of pos and lens before i meant.

They are just placeholders for the two parameters that the [m]substr()[/m] function expects. For example, if I have a string [m]str = "Hello!";[/m], then [m]str.substr(1,2)[/m] will return "el" because we start at position 1 (the second character) and are getting 2 characters.