Very Inefficient translator.

I am trying to make a code translator where you would type in a certain number and it would spit out a certain letter. I'm a total newb so I'm guessing this is the most inefficient way of doing this.
Here's the code. If there are bugs don't be surprised.

Code:

---

#include <iostream.h>
#include <stdio.h>

using namespace std;
int main(){
    int translate;
    while(translate!=0){
        cout<< "translate?";
        cin>> translate;
    }   
    if (translate==1){
        cout<< "a";
    }else{   
        while(translate!=0){
        cout<< "translate?";
        cin>> translate;
    }   
    if (translate==2){
        cout<< "b";
    }else{   
        while(translate!=0){
        cout<< "translate?";
        cin>> translate;
    } 
    return 0;
}

---

look up the ascii values for each letter, and then add the first value to their input-1, then cast it to a charater...


try something along these lines

Code:

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cin>>integer;
integer=integer-1+65;  //65 is the ASCII value for 'A', and 97 is the ASCII value for 'a'
character=static_cast<char>(integer);  //maybe a reinterpret_cast ?
cout<<character;

---

use this as a reference

>>integer=integer-1+65;
>>use this as a reference
Rather, use 'A' ;)

Quote:

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Originally Posted by Hunter2

>>integer=integer-1+65;
>>use this as a reference
Rather, use 'A' ;)

---

heh... yeah, what he said... or, if you really want to use the integer, you can just use 64... (-1+65)

I just used the integer value so he could get the basic idea of the whole ASCII thing...

Mapping an numeric value or symbol to a letter is called developing a character set. The ASCII character set referenced by the previous posts is one of the standard character sets available, but you can create your own. This is one step in the process of encryption, because you translate a known value to one that makes sense only if you know the conversion/translation. if/else statements, switch statement, and maps are relatively simple mechanisms to accomplish this.

if(num == 1)
cout << 'a';
else if (num == 3791)
cout << 'b';
else if (num = -53.21)
cout << 'c';
.
.
.
else if(num == 5e367)
cout << 'z';

The translation/conversion can be whatever you want.

Could you do this with a sequence of numbers?
For example, if you typed in 1,2,3 separated by commas it would spit out a,b,c. Think this is possible?

You mean something like this?

Code:

---

int numbers[3];
int i;
cout << "enter three numbers" << endl;
 
for(i = 0; i < 3; ++i)
  cin >> numbers[i];
 
for(i = 0; i < 3; ++i)
{
  if(numbers[i] == 0)
        cout << 'a';
  else if(numbers[i] == 1)
        cout << 'b';
  else
        cout << "no char to correspond to the number entered" << endl;
}

---

Ya, I think that would be doable. They should be space or other whitespace delimited rather than comma delimited to use this syntax, but sure. If you have to have comma delimited numbers, then read the input as a string rather than individual char, parse out the numbers out of the string and put them in the array, run the translation and display as desired. You can have the output statement put commas between the letters if so desired, too.

Cool.

Here's another idea I got.
You could declare all the variable in the beginning like.

Code:

---

int a=1
int b=2
int c=3
//etc.

---

Then you could change the users input, for now lets use "a", and make it display the value of "a". So when the user types "a" the program would see "a" and then display 1.

Very confusing. Even to me. :D

>>So when the user types "a" the program would see "a" and then display 1.
Wouldn't work. The closest you'll get to this is:

Code:

---

int convert[256];

convert['a'] = 1;
convert['b'] = 2;
//etc.

OR

std::map<char, int> convert;
convert['a'] = 1;
convert['b'] = 2;
etc.

---

The first method is more efficient, but the second is more expandable.

Quote:

---

Originally Posted by Hunter2

>>So when the user types "a" the program would see "a" and then display 1.
Wouldn't work. The closest you'll get to this is:

---

OR, you could reverse what I already gave you:

Code:

---

#include<iostream>
using namespace std;

int main()
{
    cout<<static_cast<int>('A')-64<<','<<static_cast<int>('a')-96;
    //you could also put the subtraction inside:
    //cout<<static_cast<int>('A'-64)<<','<<static_cast<int>('a'-96);
    cin.get();
    return 0;
}

---

the only thing with that is if you want 'A' and 'a' to have the same numeric value, you'll need to test to see if it's a capital letter first and then use the correct number to subtract from it...

same thing the other way... if you want 'A' and 'a' both to be the same, you'll need to change the case internally and then cast it to an int...

Quote:

---

OR, you could reverse what I already gave you:

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If you read xenoforce's latest post again, you'll see why I said what I said ;) I was just saying that you can't simply declare a variable called 'a' and have the character 'a' in a string automatically map to the variable's value. To clarify, what I meant was, the closest you'll ever get to direct name of variable-to-value of variable mapping is with a hash table or map.

Quote:

---

the only thing with that is if you want 'A' and 'a' to have the same numeric value, you'll need to test to see if it's a capital letter first and then use the correct number to subtract from it...

---

You could also use the tolower() or toupper() functions to make sure the case is what you want. I'm not sure if they're standard though.

Quote:

---

Originally Posted by Hunter2

You could also use the tolower() or toupper() functions to make sure the case is what you want. I'm not sure if they're standard though.

---

I'm pretty sure they are... that's what I meant, but I didn't want to say it exactly...

Nevermind what I said.I got a better way of explaining it now.
Sorry :rolleyes:
What I really meant to say was that if the user typed in the name of the variable, the program would display the variable's value.
I feel much better now. :D

>>if the user typed in the name of the variable, the program would display the variable's value.

Yes, in that case the closest you'll get is with a std::map or hash table. Kind of neat if you want to try writing a scripting engine, to be able to 'declare' and use variables on-the-fly :)

Quote:

---

Originally Posted by Hunter2

>>if the user typed in the name of the variable, the program would display the variable's value.

Yes, in that case the closest you'll get is with a std::map or hash table. Kind of neat if you want to try writing a scripting engine, to be able to 'declare' and use variables on-the-fly :)

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If I knew what that meant, I would be like this guy :D but since I don't I am like both of these smilies. :confused: :mad:

I just meant:

Code:

---

std::map<std::string, int> variables;
 
variables["myVar1"] = 10;
 
std::cout << variables["myVar1"];

---

So you can sort of 'declare' a new variable called "myVar1", and use it (sort of like Visual Basic without the 'option explicit'). It's not exactly the same (it's really just inserting a string/int pair into a std::map and looking up the int that goes with the string), but it looks like it and it's sort of neat anyway ;)