package com.kuang.scanner; import java.util.Scanner; //===================== //Demo04 //===================== public class Demo04 { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); //从键盘接受数据 int i = 0; float f = 0.0f; System.out.println("请输入整数: "); //如果..那么 if (scanner.hasNextInt()){ i = scanner.nextInt(); System.out.println("整数数据: "+ i); }else{ System.out.println("输入的不是整数数据!"); } //如果..那么 System.out.println("请输入小数: "); if (scanner.hasNextFloat()){ f = scanner.nextFloat(); System.out.println("小数数据: "+ f); }else{ System.out.println("输入的不是小数数据!"); } scanner.close(); } }
package com.kuang.scanner; import java.util.Scanner; //===================== //Demo05 //===================== public class Demo05 { public static void main(String[] args) { //我们可以输入多个数字, 并求其总和平均数, 每输入一个数字用回车确认, 通过输入非数字来结束输入并输出执行结果; Scanner scanner = new Scanner(System.in); //和 double sum = 0; //计算输入了多少个数字 int m = 0; System.out.println("请输入数据:"); //通过循环判断是否还有输入, 并在里面对每一次进行求和与统计 while (scanner.hasNextDouble()){ double x = scanner.nextDouble(); m = m + 1; //m++ sum = sum + x; System.out.println("你输入了第"+m+"个数据, 然后当前结果sum="+sum); } System.out.println(m + "个数的和为" + sum); System.out.println(m + "个数的平均值是" + (sum / m)); scanner.close(); } }