Question

哟伙计们，我试图在java中工作一点，因为我刚开始学习它，但如果打印一个数组你怎么能循环呢？你可以回来然后你回到这里

System.out.println("Kies een stof waar je meer info over wil: goud, zilver of tin");
System.out.println("type hem hieronder in en druk dan op enter!");

我希望你能帮助我：D。

package javaproject1;

import java.util.Scanner;

public class JavaProject1 {
    public static void main(String[] args) {
        Scanner Stof = new Scanner(System.in);
        String[] MainArr = new String[3];
        MainArr[0] = "Goud";
        MainArr[1]= "Zilver";
        MainArr[2]="Tin";
        int x = 1;
        System.out.println("Kies een stof waar je meer info over wil: goud, zilver of tin");
        System.out.println("type hem hieronder in en druk dan op enter!");
        if(Stof.next().equals(MainArr[0]));{
            System.out.println("Het is een metaal");
            System.out.println("Atoomnummer is 79");
            System.out.println("EN-waarde is 2,54");
        }
        if(Stof.next().equals(MainArr[1]));{
            System.out.println("Het is een metaal");
            System.out.println("Atoomnummer is 47");
            System.out.println("EN-waarde is 1,93");
        }
        if(Stof.next().equals(MainArr[2]));{
            System.out.println("Het is een metaal");
            System.out.println("Atoomnummer is 50");
            System.out.println("EN-waarde is 1,96");
        }
     }
 }

Answer 1

你把分号放在不应该的地方。

public String doInBackground(String... params) {


        String reg_url="http://10.0.2.2/webapp/Register.php";
        String login_url="http://10.0.2.2/webapp/login.php";
       String method= params[0];
if (method.equals("login")) {
                String login_name = params[1];
                String login_pass = params[2];
                try {
                    URL url = new URL(login_url);
                    HttpURLConnection httpURLConnection=(HttpURLConnection)url.openConnection();
                    httpURLConnection.setRequestMethod("POST");
                    httpURLConnection.setDoOutput(true);
                    httpURLConnection.setDoInput(true);
                    OutputStream os = httpURLConnection.getOutputStream();
                    BufferedWriter bufferedWriter= new BufferedWriter(new OutputStreamWriter(os,"UTF-8"));
                    String data = URLEncoder.encode("login_name","UTF-8")+"="+URLEncoder.encode(login_name,"UTF-8")+"&"+
                            URLEncoder.encode("login_pass","UTF-8")+"="+URLEncoder.encode(login_pass,"UTF-8");

                    bufferedWriter.write(data);
                    bufferedWriter.flush();
                    bufferedWriter.close();
                    os.close();

                    InputStream inputStream=httpURLConnection.getInputStream();
                    BufferedReader bufferedReader= new BufferedReader(new InputStreamReader(inputStream,"iso-8859-15"));
                    String response="";
                    String line="";
                    while ((line=bufferedReader.readLine())!=null)
                    {
                        response+=line;
                    }
                    bufferedReader.close();
                    inputStream.close();
                    httpURLConnection.disconnect();
                    return response;

                }
            return null;

就个人而言，我会在一个无限循环中循环，并选择让用户使用if(Stof.next().equals(MainArr[0])); <---- This will produce unexpected results.突破循环。

我还将用户从break中的选项保存在变量stof中。

建议：您可以做的最好的英语代码。

完整代码

gekozenStof

Answer 2

伟大的免费IDE是Eclipse或IntelliJ IDEA社区版。

好的简单循环应该这样做。

while(some condition){
    //your code
}

有问题的循环

2 个答案:

完整代码