2.11（人口统计）重写编程练习题1.11，提示用户输入年数，然后显示这个年数之后的人口值。将编程练习题1.11中的提示用于这个程序。 下面是一个运行示例： Enter the number of years:5 The population in 5 years is 325932969
2.11(Population projection) Rewrite Programming Exercise 1.11 to prompt the user to enter the number of years and display the population after the number of years. Use the hint in Programming Exercise 1.11 for this program. Here is a sample run of the program: Enter the number of years:5 The population in 5 years is 325932969
参考代码：
package chapter02; import java.util.Scanner; public class Code_11 { public static void main(String[] args) { final double BORN_NUMBER = 1.0 / 7; // Births per second final double DEAD_NUMBER = 1.0 / 13; // Deaths per second final double IMMIGRANT_NUMBER = 1.0 / 45; // Number of immigrants per second final int SECONDS_IN_A_YEAR = 365 * 24 * 60 * 60; // Seconds in a year int year; System.out.print("Enter the number of years:"); Scanner YearInput = new Scanner(System.in); year = YearInput.nextInt(); int SecondsInTheYear = SECONDS_IN_A_YEAR * year; int PopulationNumberNow = 312_032_486; int YearPopulation =(int)(PopulationNumberNow + SecondsInTheYear * BORN_NUMBER - SecondsInTheYear * DEAD_NUMBER + SecondsInTheYear * IMMIGRANT_NUMBER); System.out.println("The population in " + year + " years is "+ YearPopulation); YearInput.close(); } } 结果显示： Enter the number of years:5 The population in 5 years is 325932969 Process finished with exit code 0