Function/For loop help

[marcb]

I am trying to write a program that will translate phone numbers with letters in them into only numbers (ex. 1-800-flowers --> 1-800-3569377), but i am only getting blank lines or random numbers in return

  5 #include <iostream>
  6 #include <string>
  7
  8 char letter(char ch)
  9 {
 10         switch (ch)
 11         {
 12                 case 'A':
 13                 case 'a':
 14                 case 'B':

---------- every case and number is then listed ----

 93                  return 9;
 94                 break;
 95
 96                 case '1':
 97                  return 1;
 98                 break;
 99
100                 case '0':
101                  return 0;
102                 break;
103
104         }
105 }
106
107 #include <iostream>
108 #include <string>
109 using namespace std;
110
111 int main()
112 {
113         int length, i;
114         char ch;
115         string phone, result;
116
117         length = phone.length();
118
119         cout << "Enter the phone number" << endl;
120         cin >> phone;
121
122         for(i = 0; i < length; i++)
123         {
124                 ch = phone.at(i);
125                 letter(ch);
126                 cout << ch;
127         }
128         
129
130 return 0;
131 }

ive tried switching around variables but i'm really trying to get this function to work and its pissin me off

[Enoizat]

for(i = 0; i < length; i++)
{
    ch = phone.at(i);
    letter(ch);
    cout << ch;
}

You pass “ch” by copy and than you don’t save letter() return value.

You'd better not to declare any variable until you need it: you could easily get rid of many of yours.
Compare:

// Provided:
//          2abc     3def
// 4ghi     5jkl     6mno
// 7pqrs    8tuv     9wxyz
#include <iostream>
#include <string>

char letter(char ch);

int main()
{
    std::cout << "Enter the phone number: ";
    std::string phone;
    std::cin >> phone;

    for(size_t i = 0; i < phone.length(); ++i) { std::cout << letter(phone.at(i)); }

    std::cout << '\n';
    return 0;
}

char letter(char ch)
{
    switch (ch)
    {
    case 'A': case 'a': case 'B': case 'b': case 'C': case 'c':
        return '2';
    case 'D': case 'd': case 'E': case 'e': case 'F': case 'f':
        return '3';
    case 'G': case 'g': case 'H': case 'h': case 'I': case 'i':
        return '4';
    case 'J': case 'j': case 'K': case 'k': case 'L': case 'l':
        return '5';
    case 'M': case 'm': case 'N': case 'n': case 'O': case 'o':
        return '6';
    case 'P': case 'p': case 'Q': case 'q': case 'R': case 'r': case 'S': case 's':
        return '7';
    case 'T': case 't': case 'U': case 'u': case 'V': case 'v':
        return '8';
    case 'W': case 'w': case 'X': case 'x': case 'Y': case 'y': case 'Z': case 'z':
        return '9';
    default: return ch;
    }
}