010 输入流Scanner

输入流

类Scanner

常用方法

• next() //对输入前后空格会自动去掉，只去第一个字符串
• hasNext()
• nextLine() //获取回车前的输入的所有字符
• hasNextLine()
• close()
• hasNextInt()
• nextInt()
  等等

调用完可关闭避免占用系统资源

eg：next

public class Interaction {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("使用next接收：");
        if (scanner.hasNext()) {
            String str = scanner.next();
            System.out.println("next:" + str);    //str在if块中定义，所以作用在该块中
        }
        scanner.close();
    }
}

eg：nextline

public class Interaction {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("使用nextline接收：");
        if (scanner.hasNextLine()) {
            String str = scanner.nextLine();
            System.out.println("nextline:" + str);
        }
        scanner.close();
    }
}