如何在JAVA中检查输入是整数还是字符串等？ [英] How can I check if an input is a integer or String, etc.. in JAVA?

问题描述

我想知道如何检查用户的输入是否是某种原始类型（我的意思是整数，字符串等......我认为它是原始类型？）。我希望用户输入内容，然后检查它是否是字符串，并相应地执行某个操作。 （JAVA）
我见过这样的代码：

I am wondering how I can check if a user's input is a certain primitive type (I mean integer, String, etc... I think it's called primitive type?). I want a user to input something, then I check if it's a String or not, and do a certain action accordingly. (JAVA) I have seen some codes like this:

if (input == (String)input) { (RANDOM STUFF HERE) }

或类似的东西

if input.equals((String) input)

他们不工作。我想知道我怎么能只检查一个字符串？（已编辑）
我想知道是否有一个功能可以做到这一点？感谢您的回答

And they don't work. I want to know how I can Check for only a String? (EDITED OUT) I was wondering if there was a function that can do that? Thanks for the answers

编辑：在每个人的帮助下，我创建了我想要的固定代码：

With the help of everyone I have created my fixed code that does what I want it to:

package files;
import java.util.*;
public class CheckforSomething {
static Scanner inputofUser = new Scanner(System.in);    
static Object userInput;
static Object classofInput;
public static void main(String[] args){
    try{
    System.out.print("Enter an integer, only an integer: ");
    userInput = inputofUser.nextInt();

    classofInput = userInput.getClass();
    System.out.println(classofInput);
    } catch(InputMismatchException e) {
        System.out.println("Not an integer, crashing down");

    }

 }



 }

不再需要答案了，谢谢！

No need for answers anymore, thanks!

推荐答案

使用 instanceof 根据您的类型检查类型和类型转换：

Use instanceof to check type and typecast according to your type:

 public class A {

    public static void main(String[]s){

        show(5);
        show("hello");
    }
    public static void show(Object obj){
        if(obj instanceof Integer){
            System.out.println((Integer)obj);
        }else if(obj instanceof String){
            System.out.println((String)obj);
        }
    }
}

这篇关于如何在JAVA中检查输入是整数还是字符串等？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！