C++ Tutorial/string/string subscript indexer

Accessing characters in a string

<source lang="cpp">#include <iostream>

1. include <string>
2. include <cctype>

using std::cout; using std::cin; using std::endl; using std::string; int main() {

 string text = "asdffdsaasdf";

 int vowels = 0;              
 int consonants = 0;          
 for(int i = 0 ; i < text.length() ; i++)
   if(std::isalpha(text[i]))  
     switch(std::tolower(text[i])) {
       case "a": case "e": case "i":
       case "o": case "u":
         vowels++;
         break;
       default:
         consonants++;
     }
 cout << "Your input contained "
      << vowels     << " vowels and "
      << consonants << " consonants."
      << endl;
 return 0;

}</source>

Your input contained 3 vowels and 9 consonants.

accessing characters in string objects

<source lang="cpp">#include <iostream>

 #include <string>  
 using namespace std;  
   
 int main(){  
    char charray[80];  
    string word;  
   
    cout << "Enter a word: ";  
    cin >> word;  
    int wlen = word.length(); 
   
    cout << "One character at a time: ";  
    for(int j=0; j<wlen; j++)  
       cout << word.at(j);    
   
    word.copy(charray, wlen, 0);
    charray[wlen] = 0;          
    cout << "\nArray contains: " << charray << endl;  
      return 0;  
 }</source>

Is it a string::npos

<source lang="cpp">#include <iostream>

1. include <string>

using namespace std; int main() {

   string word1 = "Game";
   string word2("Over");
   string word3(3, "!");
   string phrase = word1 + " " + word2 + word3;
   cout << phrase << endl;

   if (phrase.find("eggplant") == string::npos)
       cout << ""eggplant" is not in the phrase.\n\n";
   return 0;

}</source>

Modify char in a string by indexer

<source lang="cpp">#include <iostream> using std::cout; using std::endl;

1. include <string>

using std::string; int main() {

  string string1( "cat" );
  string string2;
  string string3;
  string2 = string1;
  string3.assign( string1 );
  
  cout << "string1: " << string1 << "\nstring2: " << string2
     << "\nstring3: " << string3 << "\n\n";
  string2[ 0 ] = string3[ 2 ] = "r";
  cout << "string1: " << string1 << "\nstring2: " << string2 << "\nstring3: ";

  return 0;

}</source>

string1: cat
string2: cat
string3: cat
string1: cat
string2: rat
string3: "

switch statement based on char value

<source lang="cpp">#include <iostream>

1. include <string>
2. include <cctype>

using std::cout; using std::cin; using std::endl; using std::string; int main() {

 string text = "asdffdsaasdf";

 int vowels = 0;              
 int consonants = 0;          
 for(int i = 0 ; i < text.length() ; i++)
   if(std::isalpha(text[i]))  
     switch(std::tolower(text[i])) {
       case "a": case "e": case "i":
       case "o": case "u":
         vowels++;
         break;
       default:
         consonants++;
     }
 cout << "Your input contained "
      << vowels     << " vowels and "
      << consonants << " consonants."
      << endl;
 return 0;

}</source>

Your input contained 3 vowels and 9 consonants.