比萨类问题中的标识符预期误差

Question

我不断得到一个标识符预期错误，它在我的代码末尾显示“public double calcTotal（calcCost）{”。请注意，我正在从另一个类调用一个方法。有什么问题？此外，请随时指出您在我的代码中看到的任何其他错误。我很害怕，一旦我解决了这个错误，当我再次尝试编译时会弹出10个以上。谢谢！

public class PizzaOrder {
  private String [] m_Pizza; //array for base type Pizza
  private int m_numPizzas;

  //default constructor
  public PizzaOrder() {
    m_Pizza = null;//new String[0]
    m_numPizzas = 0;
  }

  //overloaded Pizza
  public PizzaOrder(String [] Pizza, int numPizzas) {
    m_Pizza = Pizza;
    m_numPizzas = numPizzas;
  }

  //public methods
  public void setPizza (String [] Pizza){
    m_Pizza = Pizza;
  }
  public String getPizza () {
    return m_Pizza;
  }
  public void setNumPizzas (int numPizzas) {
    m_numPizzas = numPizzas;
  }
  public int getNumPizzas () {
    return numPizzas;
  }

  public void addPizza(Pizza pizza) {
    if (m_Pizza.length() <= m_numPizzas) {
      m_Pizza.length() = m_numPizzas;
      //m_Pizza[m_numPizzas] = Pizza; //pizza array has same amount of items as numPizzas
      m_numPizzas++;
    }
    else {
      System.out.println("Adding an additional pizza was unuccessful.");
    }
  }

public double calcTotal(calcCost){
    double totalCost = 0;
    double Cost = calcCost(); //calling calcCost function
    for (int i = 0; i < m_Pizza.length(); i++) { //goes through array
      calcCost(m_Pizza[i]); //calculates cost for each pizza in array
      Cost += totalCost; //adds each cost to total
    return totalCost;
    }
  }

  public String toString() {
    double total = calcTotal(calcCost); //stores calcTotal function in total variable
    System.out.println("You ordered a " + m_Pizza + ". Your total cost is: " + total);
  }

}

Answer 1

是的，这个方法似乎有很多问题，我已经添加了评论

public double calcTotal(calcCost){
  double totalCost = 0;
  double Cost = calcCost(); // is there really a zero parameter method ?
  for (int i = 0; i < m_Pizza.length(); i++) { 
    calcCost(m_Pizza[i]); // this takes a parameter but does not use the return value
    Cost += totalCost; // totalCost is always zero, do you mean totalCost += Cost; ?
    return totalCost;  // you are returning this value with in the for loop
  }

  // compile error here as it is expecting some value to be returned

}

提示：将返回值移到循环外部

将calCost的价值保存到成本

将Cost的值添加到totalCost

同样，@ markspace提到这个方法的参数有问题，实际上是否需要？

Answer 2

在循环结束后，您应该在方法结束时添加“return”语句。

 public double calcTotal(calcCost){
    double totalCost = 0;
    double Cost = calcCost(); //calling calcCost function
    for (int i = 0; i < m_Pizza.length(); i++) { //goes through array
      calcCost(m_Pizza[i]); //calculates cost for each pizza in array
      Cost += totalCost; //adds each cost to total

    }
    return totalCost;
  }

想想当m_Pizza变量为空时，控件不会进入for循环然后返回什么方法？所以上面是修复。