c++ - 运行时检查错误3以防万一

Question

我的程序已经弄清楚了一半，除了当我去立方一个数字/平方一个数字/显示奇数或偶数而不输入数字时，而不是简单地说明“您还没有输入数字”我得到了运行检查错误 #3 然后是一个非常大的负数。这显然不是我想要发生的事情。

#include<stdlib.h>
#include<stdio.h>


//begin function
int main ()
{

//declare variables
int choice;
int number = 0;
int cubed;
int squared;

//menu and begin do while loop
do {


printf("***********************\n");
printf("--Main Menu---\n");
printf("***********************\n");
printf("1.Enter a number\n");
printf("2.Cube the number\n");
printf("3.Square the number\n");
printf("4.Display Even or Odd\n");
printf("5.Quit\n");

printf("Enter your choice:   ");
scanf("%i", &choice);

printf("Your current number is: %i \n", number);

//begin switch and functions
switch(choice){

 case 1: 
      printf("Enter a number\n");
      scanf("%i", &number);
break;

case 2:  

      if (number == 0)
      printf("You have not entered a number\n");
      else 
      cubed= number * number * number;
      printf("Your number cubed is: %i \n", cubed);
break;

case 3:
       if (number == 0)
       printf("You have not entered a number\n");
       else
       squared=  number * number;
       printf("Your number squared is: %i \n", squared);
break;
case 4:
      if (number == 0)
       printf("You have not entered a number\n");
       else if
      (number % 2 ==0)
      printf("Your number squared is even!\n");

      else 

      printf("Your number is odd!\n");

break;

case 5:
      printf("Goodbye!!!!\n");
system("pause");
break;

default:
      printf("Was not 1 through 5\n");
break;
}// end switch and functions








} while (choice!=5); 


} //end function

Answer 1

C 不会初始化变量，因此您必须这样做。如果你不初始化，你的变量将等于内存位置的任何内容，因此它是不可预测的。在您的情况下，您应该用负值初始化数字以强制首先输入数字。整数数=-1;