java - Java新手-If-其他If问题

我只是在学习Java，并且完全被这部分代码所困扰。我环顾四周，但是部分语言知识是知道要问的正确问题，而且我已经没有足够的想法去搜索了。一切对我来说都不错，但我希望有更多经验的人能够对我有所了解。

每当我执行此代码或逐步执行时，无论温度是100到213（无论摄氏还是华氏度），Else If都会一直运行。谁能启发我为什么会发生这种情况，或者将我推向正确的思维框架？这是代码：

package chapter.pkg3;

import java.util.Scanner;

public class Chapter3 {

public static void main(String[] args) {

    Scanner in = new Scanner(System.in);
    System.out.print("Please enter the temperature: ");
         double temp = in.nextDouble();
    System.out.print("Please enter the temperature measurement, C or F: ");
         String measure = in.next();
     if (measure.equals("C"))
        { measure = "Celsius";}
     else
        {measure = "Fahrenheit";}
     if ((temp <= 0 && measure.equals("C")) || (temp <= 32 && !measure.equals("C")))
        {
        System.out.print("The temperature is " + temp + " " + measure + ".  The water
        is freezing!");
        }
     if ((temp <= 100 && measure.equals("C")) || (temp <= 212 && !measure.equals("C")))
        {
        System.out.print("The temperature is " + temp +  " " + measure + ".  The water
        is liquid.");
        }
     if ((temp > 100 && measure.equals("C")) || (temp > 212 && !measure.equals("C")))
        {
        System.out.print("At " + temp + " " + measure + " the water has become gas.");
        }
  }

}

先谢谢您的帮助！

最佳答案

在像if这样的temp <= 0 && measure.equals("C")条件中，条件measure.equals("C")将始终为false，因为您在此处覆盖了变量measure的值：

if (measure.equals("C"))
   {measure = "Celsius";}
else
   {measure = "Fahrenheit";}