If and else Statements in While loop" for C++ - c++

Question

I have a question regarding if & else statements in a while loop.
I wanted to establish a few things in my program:
wanted user to only input 4 letter characters without the use of numbers and symbols.
converting each those letters into ints(Ascii val.)
To make it easier to understand if confused,
Program 1st asks for 4 letter word.
User places input. If input contains at least:
a non-letter character, then Program asks User for new Input.
If input only contain letters Program checks input for # of letters.
If input doesn't have ___ :
4 letters, Program asks User for new Input.
Otherwise Program proceeds with determining Int value of each letter
Okay so heres my Program so far: ** not sure if this correct for
#include <iostream>
using namespace std;
int main() {
string input;
int input0 = input[0];
int input1 = input[1];
int input2 = input[2];
int input3 = input[3];
cout << "\nEnter a 4-letter word (Keep it clean!).\n";
while(cin>>input){
cout << endl << input << " has " << input.length() << " letters." << endl;
if (int(input[0]) > 64 || int(input[0]) < 91 || int(input[0]) > 96 || int(input[0]) < 123 ||
int(input[1]) > 64 || int(input[1]) < 91 || int(input[1]) > 96 || int(input[1]) < 123 ||
int(input[2]) > 64 || int(input[2]) < 91 || int(input[2]) > 96 || int(input[2]) < 123 ||
int(input[3]) > 64 || int(input[3]) < 91 || int(input[3]) > 96 || int(input[3]) < 123) {
if (input.length()!=5 && input.length()>3)
cout << "\n the int value of the " << input[0] << " is " << int(input[0]) << endl;
cout << "\n the int value of the " << input[1] << " is " << int(input[1]) << endl;
cout << "\n the int value of the " << input[2] << " is " << int(input[2]) << endl;
cout << "\n the int value of the " << input[3] << " is " << int(input[3]) << endl;
else cout << input << "is not a 4-letter word.\nPlease try again." << endl;
}
else cout << input << " contains number(s) and or symbol(s).\nPlease try again." << endl;
}
}
I got 2 errors:
error: expected '}' before 'else'
error: 'else' without a previous 'if'

Answer 1

This fairly gnarly bunch of statements is to blame:
if (input.length()!=5 && input.length()>3)
cout << "\n the int value of the " << input[0] << " is " << int(input[0]) << endl;
// Not part of if-statement:
cout << "\n the int value of the " << input[1] << " is " << int(input[1]) << endl;
cout << "\n the int value of the " << input[2] << " is " << int(input[2]) << endl;
cout << "\n the int value of the " << input[3] << " is " << int(input[3]) << endl;
else cout << input << "is not a 4-letter word.\nPlease try again." << endl;
You need to enclose all those cout statements (up until the else) in braces {, }.
I'd just like to make a point about the character tests you're doing. It looks like you're checking whether the characters are letters, but are using the least-readable, least-portable approach. Use std::isalpha instead. In fact, you can accomplish the whole thing with this:
if( std::all_of( input.begin(), input.begin() + 4, [](char c){ return (bool)isalpha(c); } ) )
{
//...
}
You should do the tests after ensuring the input is the correct length, or you will have undefined behaviour. So let's do that:
while( cin>>input )
{
cout << endl << input << " has " << input.length() << " letters." << endl;
if( input.length() != 4 )
{
cout << input << "is not a 4-letter word.\nPlease try again." << endl;
}
else if( any_of( input.begin(), input.end(), [](char c){ return !isalpha(c); } ) )
{
cout << input << " contains number(s) and or symbol(s).\nPlease try again." << endl;
}
else
{
// I assume you want to exit the loop here.
break;
}
}
Notice I flipped the all_of statement around to the inverse ("any character is not a letter"), for better readability because the lambda no longer needs a cast for automatic type-deduction:
if( any_of( input.begin(), input.end(), [](char c){ return !isalpha(c); } ) ) ...