Java Scanner 类——获取用户的输入

创建Scanner对象语法

Scanner scan = new Scanner(System.in);

使用next()获取输入的字符串

import java.util.Scanner;

public class ScanTest1 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        if (scanner.hasNext()) {
            String str1 = scanner.next();
            System.out.println("Input:" + str1);
        }
        scanner.close();
    }
}

使用nextLine()获取字符串

public class ScanTest2 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        if (scanner.hasNextLine()) {
            String str1 = scanner.nextLine();
            System.out.println("Input:" + str1);
        }
        scanner.close();
    }
}

以上二者区别

nextLine()见到回车就结束，而next()必须得到有效字符

next()获取第一个空格前数据（比如，输入a b c得到a，输入  a b得到a）

使用nextInt()获取整数

public class ScanTest3 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        if (scanner.hasNextInt()) {
            int str1 = scanner.nextInt();
            System.out.println("Input:" + str1);
        }
        scanner.close();
    }
}

同样，还有nextShort, nextFloat, nextDouble, nextBoolean, nextByte,  nextChar, nextBigInteger, nextBigDecimal...