从循环中取值？

Question

这是一个程序，用于查明某人的年龄应该是一年中的平方根。我如何从这个循环中选择一个年龄和关联年份，以便我可以打印它？

package squareAges; 

import javax.swing.JOptionPane; 
import java.util.Scanner; 
import java.lang.Math; 

public class SquareAges { 

    public static final int MIN_YEAR = 1893; 
    public static final int MAX_YEAR = 2139; 

    public static void main(String[] args) { 

     for (int age = 0; age <= 123; age++) { 
      System.out.println(age + "= " + age * age + " "); 

      if (MIN_YEAR <= (age * age) && (age * age) <= MAX_YEAR) { 
       JOptionPane.showMessageDialog(null, "It is possible that someone alive today " 
         + "has, is, or will be  alive in a year that is the square of their age."); 
      } 
     } 
    } 
} 

谢谢。

Answer 1

如果你只想打印特别值满足你的上述条件，则可以使用如果循环内，代码可以是这样的：

int age, year; 
for (year = 1893; year <= 2139; year++) { 
    for (age = 0; age <= 123; age++) { 
     System.out.println(age + "= " + age * age + " "); 

     if (MIN_YEAR <= (age * age) && (age * age) <= MAX_YEAR) { 
      JOptionPane.showMessageDialog(null, "It is possible that someone alive today " 
        + "has, is, or will be  alive in a year that is the square of their age."); 

      if (age * age == year) { 
       System.out.println("Age is:" + age + "Year is:" + year); 
      } 
     } 
    } 

} 

Answer 2

1. 在循环外引入局部变量。
2. 将它指定为if声明。
3. 做break在if声明。
4. 循环后使用局部变量。