Question

我是c ++的初学者，我有一个简单计算器的代码，但它有一些错误。

此错误：[警告]转换为int' from float' 在第68行（copy = operand1）。
和这一个：在函数`int main（）'：

如何修复这些错误？事先感谢您的帮助;

#include <iostream>
#include <iomanip>
using namespace std;

struct Node{
    float number;
    Node *next;
};

Node* push(Node *stack, float data){
  Node *utility;
  utility = new Node;
  utility -> number = data;
  utility -> next = stack;
  return utility;
}

Node* pop(Node *stack, float &data){
  Node *temp;
  if (stack != NULL){
    temp = stack;
    data = stack -> number;
    stack = stack -> next;
    delete temp;
  }
  else cout << "\nERROR: Empty stack.\n";
  return stack;
}

int main()
{
  float answer=0.f, operand1=0.f, operand2=0.f;
  char ch = ' ';
  int neg=0,cont=0,copy;
  Node *utility, *top;

  utility = new Node;
  utility -> number = 0.f;
  utility -> next = NULL;
  top = new Node;
  top -> number = 0.f;
  top -> next = utility;

  cout << "Enter the postfix operation: ";
 while(ch != '\n')
    {
        cin >> noskipws >> ch;
        cont++;    
        if(cont<4&&ch=='-'){
                neg=-1;
                ch=' ';
        }
        int operand = 0;
        while(ch == ' '){
          cin >> ch;
        }      
        if((ch >= '0')&&(ch <= '9')){
          while(ch != ' '){
            operand = operand*10 + (ch-48);
            cin >> ch;
            if(neg==-1 && operand1>=0 ){
                operand=operand * neg;
            }
          }
          neg=0;
          top = push(top, operand);
        }else{
          ****copy=operand1;****
          top=pop(top, operand1);
          top=pop(top, operand2);
          if(operand2<0&&copy>0){
              operand2*=-1;
              if(cont>4)
                  operand2*=-1;
          }
          switch(ch){
            case '+': answer = operand2 + operand1;break;
            case '-': answer = operand2 - operand1;break;
            case '*': answer = operand2 * operand1;break;
            case '/': answer = operand2 / operand1;break;
          }
          top=push(top, answer);
        }
    }
  pop(top, answer);
  cout << "Answer: " << answer << endl;
  system("pause");
  return 0;
}

Answer 1

违规行是第68行，这是GCC 4.9.0的输出：

E：\ test.cpp：在函数＆＃39; int main（）＆＃39;：

E：\ test.cpp：68：15：错误：一元＆＃39; *＆＃39; 的无效类型参数（有＆＃39; int＆＃39;）** **复制=操作数; ****

E：\ test.cpp：68：31：错误：不匹配＆＃39;运营商*＆＃39; （操作数类型是＆＃39; Node＆＃39;）**** copy = operand1; ****

错误表明单元运算符*无法应用于int（int没有单位运算符*，只有二进制）

第68行：**** copy = operand1; ****

开头和结尾处的四个*是问题，已删除。

我该怎么处理c ++中的这个错误？

1 个答案: