java string

字符串：

package org.yuan.my_project;
import java.util.Scanner;

public class sad5 {
public static void main(String[] args)
{
for(int i = 0; i < 3 ;i ++)
{
String username ="ysys";
String password = "66666";

Scanner sc = new Scanner(System.in);

System.out.println("请输入用户的名称");
String name = sc.nextLine();

System.out.println("请输入密码");
String pwd = sc.nextLine();

if(username.equals(name)&&password.equals(pwd))
{
System.out.println("登陆成功");
break;
}
else
{
if((2-i)==0)
{
System.out.println("用户被锁定");
}

 

 

else {
System.out.println("登陆失败");
System.out.println("还有"+ (2-i) + "次机会");
}
}
//0 1 2
//3 2 1
}
}
}

　　

 

 

package org.yuan.my_project;
import java.util.Scanner;

public class sad5 {
	public static void main(String[] args)
	{
		for(int i = 0; i < 3 ;i ++)
		{
		String username ="ysys";
		String password = "66666";
		
		Scanner sc = new Scanner(System.in);
		
		System.out.println("请输入用户的名称");
		String name = sc.nextLine();
		
		System.out.println("请输入密码");
		String pwd = sc.nextLine();
		
		if(username.equals(name)&&password.equals(pwd))
		{
			System.out.println("登陆成功");
			break;
		}
		else
		{
			if((2-i)==0)
			{
				System.out.println("用户被锁定");
			}
			else {
			System.out.println("登陆失败");
			System.out.println("还有"+ (2-i) + "次机会");
		}
		}
		//0 1 2
		//3 2 1
		}
	}
}

遍历字符串
用到
lenth（）；
line.charAt();//提取一个字符

package org.yuan.my_project;
import java.util.Scanner;

public class sad5 {
	public static void main(String[] args)
	{
		Scanner sc = new Scanner(System.in);
		System.out.println("请输入一个字符串");
		
		
		String line = sc.nextLine();

		for(int i = 0; i < line.length();i++)
		{
			System.out.println(line.charAt(i));
		}
	}
}