如何使用Scanner类从控制台读取输入?就像这样:
System.out.println("Enter your username: ");
Scanner = input(); // Or something like this, I don't know the code
基本上,我想要的只是让扫描器读取用户名的输入,并将输入分配给一个String变量。
如何使用Scanner类从控制台读取输入?就像这样:
System.out.println("Enter your username: ");
Scanner = input(); // Or something like this, I don't know the code
基本上,我想要的只是让扫描器读取用户名的输入,并将输入分配给一个String变量。
当前回答
input.nextInt()方法有问题——它只读取int值。
因此,当使用input.nextLine()读取下一行时,您会收到“\n”,即回车键。所以要跳过这个,你必须添加input.nextLine()。
试着这样做:
System.out.print("Insert a number: ");
int number = input.nextInt();
input.nextLine(); // This line you have to add (it consumes the \n character)
System.out.print("Text1: ");
String text1 = input.nextLine();
System.out.print("Text2: ");
String text2 = input.nextLine();
其他回答
说明java.util.Scanner如何工作的一个简单示例是从System.in中读取单个整数。这真的很简单。
Scanner sc = new Scanner(System.in);
int i = sc.nextInt();
要检索用户名,我可能会使用sc.nextLine()。
System.out.println("Enter your username: ");
Scanner scanner = new Scanner(System.in);
String username = scanner.nextLine();
System.out.println("Your username is " + username);
如果您想对输入进行更多控制,或者只是验证用户名变量,也可以使用next(字符串模式)。
你可以在java.util.Scanner的API文档中找到更多关于它们实现的信息
下面是执行所需操作的完整类:
import java.util.Scanner;
public class App {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
final int valid = 6;
Scanner one = new Scanner(System.in);
System.out.println("Enter your username: ");
String s = one.nextLine();
if (s.length() < valid) {
System.out.println("Enter a valid username");
System.out.println(
"User name must contain " + valid + " characters");
System.out.println("Enter again: ");
s = one.nextLine();
}
System.out.println("Username accepted: " + s);
Scanner two = new Scanner(System.in);
System.out.println("Enter your age: ");
int a = two.nextInt();
System.out.println("Age accepted: " + a);
Scanner three = new Scanner(System.in);
System.out.println("Enter your sex: ");
String sex = three.nextLine();
System.out.println("Sex accepted: " + sex);
}
}
你可以流动这段代码:
Scanner obj= new Scanner(System.in);
String s = obj.nextLine();
举个简单的例子:
import java.util.Scanner;
public class Example
{
public static void main(String[] args)
{
int number1, number2, sum;
Scanner input = new Scanner(System.in);
System.out.println("Enter First multiple");
number1 = input.nextInt();
System.out.println("Enter second multiple");
number2 = input.nextInt();
sum = number1 * number2;
System.out.printf("The product of both number is %d", sum);
}
}
读取输入: 扫描仪扫描仪=新的扫描仪(System.in); 字符串输入= scanner.nextLine(); 当你调用一个带有参数/形参的方法时读取输入: 如果(arg游戏。长度!= 2){ System.err。println(" utilzare: java Grep < filier > <cuvant>"); system . exit (1); } 尝试{ grep (args [0], arg游戏[1]); } catch (IOException e) { System.out.println (e.getMessage ()); }