例5.11 输入三个字符串，要求将字母按由小到大的顺序输出。
import java.util.Scanner;
public class Demo5_11 {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String string1, string2, string3;
String temp;
System.out.println("Please input three strings:");
string1 = sc.next();
string2 = sc.next();
string3 = sc.next();
if (string2 .compareTo(string3)>0) {
temp = string2;
string2 = string3;
string3 = temp;
}
if (string1.compareTo(string2) <= 0){
System.out.println(string1+" "+string2+" "+string3);
} else if (string1.compareTo(string3) <= 0) {
System.out.println(string2+" "+string1+" "+string3);
} else {
System.out.println(string2+" "+string3+" "+string1);
}
}
}
例5.12 一个班有n个学生，需要把每个学生的简单材料（姓名和学号）输入计算机保存。然后可以通过输入某一学生的姓名查找其有关资料。当输入一个姓名后，程序就查找该班中有无此学生，如果有，则输出他的姓名和学号，如果查不到，则输出“本班无此人”。
import java.util.Scanner;
public class Demo5_12 {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String find_name;
String[] name = new String[50];
String[] num = new String[50];
int n;
System.out.print("Please input number of this class:");
n = sc.nextInt();
input_data(n,name,num);
// for (int i = 0; i < n; i++) {
// System.out.println(name[i]+num[i]);
// }
System.out.print("Please input name you want find:");
find_name = sc.next();
search(find_name,n,name,num);
}
private static void input_data(int n,String name[], String num[]) {
Scanner sc = new Scanner(System.in);
for (int i = 0; i < n; i++) {
System.out.print("Input name and NO. of student"+(i+1)+":");
name[i] = sc.next();
num[i] = sc.next();
}
}
private static void search(String find_name, int n, String name[],String num[]) {
boolean flag = false;
for (int i = 0; i < n; i++) {
if (name[i].equals(find_name)) {
System.out.println(name[i] + " has been found, his number is " + num[i]);
flag = true;
break;
}
}
if (flag == false)
System.out.println("Can't find this name");
}
}