Question

public class Chair
{
   private String typeChair;
   private String materials;
   private String color;
   private double legs;
   private double pricePerChair;

   public void setTypeChair(String t) {
      typeChair = t;
   }
   public String getTypeChair() {
      return typeChair;
   }
   public void setMaterial(String m) {
      materials = m;
   }
   public String getMaterials() {
      return materials;
   }
   public void setColor(String c) {
      color = c;
   }
   public String getColor() {
      return color;
   }
   public void setLegs(double l) {
      if (l >= 0 && l < 10) {
         legs = l;
      } else {
         System.out.println("Legs must be between 0 and 9");
      }
   }
   public double getLegs() {
      return legs;
   }
   public void setPricePerChair(double p) {
      if (p > 0) {
         pricePerChair = p;
      } else {
         System.out.println("Price must be greater than 0");
      }
   }
   public double getPricePerChair() {
      return pricePerChair;
   }
   public double getCost() {
      double cost = 0;
      if (materials == "vinyl") {
         cost += (pricePerChair * 0) + pricePerChair;
      } else if (materials == "leather") {
         cost += (pricePerChair * .4) + pricePerChair;
      } else if (materials == "cloth") {
         cost += (pricePerChair * .1) + pricePerChair;
      } 
      return cost;
   }
   }

你好，我无法从材料中获得椅子的费用。材料是从用户输入的。如果材料是乙烯基，则附加成本为0％，皮革为0.4％，布为0.1％。每次我运行我的主方法，成本打印0.什么是代码中的问题？

Answer 1

这里常见的错误 - 应始终将Java字符串与equals()方法进行比较，而不是与==进行比较。例如：

 } else if (materials.equals("cloth")) {

Answer 2

尝试.equals（）而不是==进行比较

成本无法正确打印

2 个答案: