isspace和isalpha不計數

Question

我的程序應該計算輸入字符串中的元音，輔音，數字和空格的數量。它只計算數字的數量。請幫忙。

#include<iostream> 
using namespace std; 

void counter(char string[], int count[]){ 
    int check_letter, check_digit, check_space; 
    for(int i = 0; i < 99; i++){ 
     check_letter = isalpha(string[i]); 
     if(check_letter == 1){ 
      string[i] = tolower(string[i]); 
      if(string[i] == 'a' || string[i] == 'e' || string[i] == 'i' || 
        string[i] == 'o' || string[i] == 'u'){ 
       count[0] = count[0] + 1; 
      } else{ 
       count[1] = count[1] + 1; 
      } 
     } 
     check_digit = isdigit(string[i]); 
     if (check_digit == 1){ 
      count[2] = count[2] + 1; 
     } 
     check_space = isspace(string[i]); 
     if(check_space == 1){ 
      count[3] = count[3] + 1; 
     } 
    } 
} 

main(){ 
    char string[100] = {}; 
    int count[4] = {}; 
    cout << "Please enter a string: "; 
    cin.get(string, 100); 
    cin.get(); 
    cout << string; 
    counter(string, count); 
    cout << "There are " << count[0] << " vowels.\nThere are " << count[1] << 
      " consonants.\nThere are " << count[2] << " digits.\nThere are " << 
      count[3] << " spaces."; 
} 

Answer 1

我已經修改你的程序，它適用於我。您可以直接在if（）語句中檢查isalpha（）isdigit（）的返回值，就像它們是bools一樣。

#include<iostream> 
using namespace std; 

void counter(char string[], int count[]){ 
    for(int i = 0; i < 99; i++){ 
     if(isalpha(string[i])){ 
      string[i] = tolower(string[i]); 
      if(string[i] == 'a' || string[i] == 'e' || string[i] == 'i' || 
        string[i] == 'o' || string[i] == 'u'){ 
       count[0] = count[0] + 1; 
      } else{ 
       count[1] = count[1] + 1; 
      } 
     } 
     if (isdigit(string[i])){ 
      count[2] = count[2] + 1; 
     } 
     if(isspace(string[i])){ 
      count[3] = count[3] + 1; 
     } 
    } 
} 

main(){ 
    char string[100] = {}; 
    int count[4] = {}; 
    cout << "Please enter a string: "; 
    cin.get(string, 100); 
    cin.get(); 
    cout << string; 
    counter(string, count); 
    cout << "There are " << count[0] << " vowels.\nThere are " << count[1] << 
      " consonants.\nThere are " << count[2] << " digits.\nThere are " << 
      count[3] << " spaces."; 
} 

Answer 2

你的問題是假設isalpha，isdigit等返回1當它們匹配：他們的文件說，他們返回一個非零值的「真」和零「假」。

例如，來自std::isalpha docs here：

返回值

非零如果字符是字母字符，否則爲零值。

如果存儲結果在bool，或直接在布爾上下文中測試它們（例如if (...)條件，則轉換會爲你做。

Answer 3

問題是check_letter，check_digit和check_space都應該bool而不是int。

所以，改變bool check_letter, check_digit, check_space;以及if(check_letter)而不是if(check_letter == 1)等。

另外請記住，「字符串」不是一個非常聰明的方式命名變量...