c++ - isspace 和 isalpha 不算数

Question

我的程序应该计算输入字符串中元音、辅音、数字和空格的数量。它只计算位数。请帮忙。

#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

您的问题是假设 isalpha、isdigit 等在匹配时返回 1:他们的文档说他们返回非零“true”的值和“false”的零值。

例如，来自std::isalpha docs here :

Return value

Non-zero value if the character is an alphabetic character, zero otherwise.

如果您将结果存储在 bool 中，或者直接在 bool 上下文中测试它们(例如 if (...) 条件，那么转换将是为您完成。