原文是java的内容，正好用在了Swift上，Good Job!

本文为转载文章，以下内容来源于
如何只使用switch...case来实现一个简单的数值范围划分
csdn
 
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import java.io.*;

public class tryCase1 {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
			
		int age;
		
		
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		try {
			age = Integer.parseInt(br.readLine());
					
			switch (age>0?(age>17?(age>29?(age>59?4:3):2):1):-1){
			case (1):
				System.out.println("少年");
				break;
			case (2):
				System.out.println("青年");
				break;
			case (3):
				System.out.println("中年");
				break;
			case (4):
				System.out.println("老年");
				break;
			case (-1):
				System.out.println("你输入的数值不合法");
				break;
				
			default:
				System.out.println("default");
				break;
			
			}
		} catch (NumberFormatException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

		
	}

}