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copied!<p>For context, you could have provided a link to <a href="https://stackoverflow.com/questions/1663615/translating-program">your previous question</a>, about storing two lists of words in different languages. There I provided an example of reading the contents of a text file into an array:</p> <pre><code>const int MaxWords = 100; std::string piglatin[MaxWords]; int numWords = 0; std::ifstream input("piglatin.txt"); std::string line; while (std::getline(input, line) && numWords < MaxWords) { piglatin[numWords] = line; ++numWords; } if (numWords == MaxWords) { std::cerr << "Too many words" << std::endl; } </code></pre> <p>You can't have <strong><em>one</em></strong> parallel array. For something to be parallel, there must be at least two. For parallel arrays of words, you could use a declarations like this:</p> <pre><code>std::string piglatin[MaxWords]; std::string english[MaxWords]; </code></pre> <p>Then you have two options for filling the arrays from the file:</p> <ol> <li><p>Read an entire line, and the split the line into two words based on where the first space is:</p> <pre><code>while (std::getline(input, line) && numWords < MaxWords) { std::string::size_type space = line.find(' '); if (space == std::string::npos) std::cerr << "Only one word" << std::endl; piglatin[numWords] = line.substr(0, space); english[numWords] = line.substr(space + 1); ++numWords; } </code></pre></li> <li><p>Read one word at a time, and <em>assume</em> that each line has exactly two words on it. The <code>>></code> operator will read a word at a time automatically. (If each line doesn't have exactly two words, then you'll have problems. Try it out to see how things go wrong. Really. Getting experience with a bug when you <em>know</em> what the cause is will help you in the future when you <em>don't</em> know what the cause is.)</p> <pre><code>while (input && numWords < MaxWords) { input >> piglatin[numWords]; input >> english[numWords]; ++numWords; } </code></pre></li> </ol> <p>Now, if you really one <em>one</em> array with <em>two elements</em>, then you need to define another data structure because an array can only have one "thing" in each element. Define something that can hold two strings at once:</p> <pre><code>struct word_pair { std::string piglatin; std::string english; }; </code></pre> <p>Then you'll have just one array:</p> <pre><code>word_pair words[MaxWords]; </code></pre> <p>You can fill it like this:</p> <pre><code>while (std::getline(input, line) && numWords < MaxWords) { std::string::size_type space = line.find(' '); if (space == std::string::npos) std::cerr << "Only one word" << std::endl; words[numWords].piglatin = line.substr(0, space); words[numWords].english = line.substr(space + 1); ++numWords; } </code></pre> <p>Notice how the code indexes into the <code>words</code> array to find the next <code>word_pair</code> object, and then it uses the <code>.</code> operator to get to the <code>piglatin</code> or <code>english</code> field as necessary.</p>

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