不使用if
package scanner;import java.util.Scanner;public class Demo03 {public static void main(String[] args) {//从键盘接收数据Scanner scanner = new Scanner(System.in);System.out.println("请输入数据");String str = scanner.nextLine();System.out.println("输出的内容为： "+str);scanner.close();}
}
nextInt()
package scanner;import java.util.Scanner;public class Demo04 {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int i = 0;float f = 0.0f;System.out.println("请输入整数： ");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！");}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();}
}
nextDouble()
package scanner;import java.util.Scanner;public class Demo05 {public static void main(String[] args) {//输入多个数字，求总和与平均值，每输入一个数据用回车确认；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("请输入整数，用回车确认；结束请输入非数字");//通过循环判断是否还有输入，并在里面对每一次进行求和和统计while (scanner.hasNextDouble()){double x = scanner.nextDouble();//m++;//m = m + 1;sum = sum + x;System.out.println("你输入了第"+m+"个数据，当前的结果sum="+sum);}System.out.println(m + "个数的和为: " + sum);System.out.println(m + "个数的平均值为: " + (sum/m));scanner.close();}
}
