如何初始化变量

Question

你好我想建立一个程序，从给定的两个数字中找到偶数和奇数。 当我构建它时它说成功但它仍然说警告C4700：使用未初始化的局部变量'number'

当我调试它时出现调试错误如何解决这个问题？ 谁能告诉我它发生的原因？ 太感谢了

下面是代码

#include<stdio.h>
#include <iostream>
using namespace std;


int main(){

    int number;
    int firstNum,secondNum;

    cout << "Enter the first number: ";
    cin >> firstNum;

   cout << "Enter the second number: ";
    cin >> secondNum;


    if(number % 2 !=0){
    for(number = firstNum;number <= secondNum; number++)
      cout << number<< " ";

    cout << "Odd numbers in given range are: ";
    cout << number<< " ";
    }
    else if(number % 2 ==0){

   for(number = firstNum;number <= secondNum; number++)
     printf("\nEven numbers in given range are: ");

             cout << number << " ";
    }
    return 0;
}

Answer 1

你的程序出错的原因是你没有初始化你的变量number 。 我已经纠正了。 几乎没有其他错误会给出错误的 output。我已经更正并重新格式化了您的代码 -

#include<stdio.h>
#include <iostream>
using namespace std;


int main(){

    int number;
    int firstNum,secondNum;

    cout << "Enter the first number: ";
    cin >> firstNum;

   cout << "Enter the second number: ";
    cin >> secondNum;

    number=firstNum;
    for(number = firstNum;number <= secondNum; number++)
      cout << number<< " ";
    //Following piece will print out all odd numbers
    cout << "\nOdd numbers in given range are: ";
    for(number = firstNum;number <= secondNum ; number++)
        if(number&1)
            cout<<number<<" ";
    cout<<"\n";    
    //Following piece will print out all even numbers        
    cout << "Even numbers in given range are: ";
    for(number = firstNum;number <= secondNum ; number++)
        if(!(number&1))
            cout<<number<<" ";
    cout<<"\n";




    return 0;
}

您可能正在尝试打印给定范围内的奇数和偶数。 上面的程序正是这样做的。

希望这能解决你的问题！

Answer 2

除了声明之外，您实际上从未在整个程序中使用过number ，也没有初始化。

此代码将帮助您了解变量number的用法：

#include <iostream>

int main(void) {
    int value1, value2, number; // declaration

    std::cout << "Enter the first number: ";
    std::cin >> value1;

    std::cout << "Enter the second value: ";
    std::cin >> value2;

    number = value1; // assigning number as temporary

    std::cout << "Even numbers in the range: ";

    for (; number <= value2; number++)
        if (number % 2 == 0) 
            std::cout << number << ' ';

    std::cout << std::endl << "Odd numbers in the range: ";

    for (; value1 <= value2; value1++)
        if (value1 % 2 == 1)
            std::cout << value1 << ' ';
    std::cout << std::endl;

    return 0;
}

小提示：避免使用using namespace std 。