使用预处理器进行调试

一、预处理指令

问题：输入一些WORD,判断有没有首字母大写的两个相同的词

#include<iostream>
#include<string>

using namespace std;

int main()
{
    string currWord, preWord;
    cout << "Enter some words:(ctrl+z to end)" << endl;
    while (cin >> currWord)
    {
#ifndef NDEBUG
        cout << endl << "调试：" << currWord << endl;  //这是调试用的
#endif
        if (!isupper(currWord[0]))
            continue;
        if (currWord == preWord)
            break;
        else preWord = currWord;
    }
    if (currWord == preWord&&!currWord.empty())
    {
        cout << "The repeated word:" << currWord << endl;
    }
    else
        cout << "没有重复的！" << endl;
    system("pause");
}

关闭预处理：

解决资源方案--demo--右键“属性”--c++--命令行----附加选项：/DNDEBUG

结果：

二、预处理常量

#include<iostream>
#include<string>

using namespace std;

int main()
{
    cout << "文件：" << __FILE__ << endl<<"行：" << __LINE__ << endl<<"日期：" << __DATE__ << endl<<"时间：" << __TIME__ << endl;
    system("pause");
}

三、assert断言

#include<iostream>
#include<assert.h>

using namespace std;

int add(int x, int y)
{
    return x * y;
}
int main()
{
    int result;
    result = add(1, 2);
    assert(result == 3);
    cout << result << endl;
    system("pause");
}

断言也用来调试，与预定义一样，受附加选项/DNDEBUG控制