Question

我有一个程序，我需要从一个方法返回，问题是他总是返回第一个位置而已。这是我想要接收输入的方法。

  public void getCountByArea() {


              //always receive the same string
              String inputToValidate = getInputsTxtFromConsole();
              String inputToCompare = getInputsTxtFromConsole();


}

这是我的另一种方法

public String getInputsTxtFromConsole() {

//read inputs file
    try {

        Scanner scanner = new Scanner(inputFile);

        //read the file line by line
        int lineNum = 0;
        while (scanner.hasNextLine()) {
            String line = scanner.nextLine();
            lineNum++;

            return line; //this always returns the same number

        }
    } catch (FileNotFoundException e) {


    }


  return "";

}

Answer 1

您不能使用return语句来获取更多的值，因为它结束了函数调用。最好的方法是堆叠值然后返回。这是使用arraylist的一个例子。

public List getInputsTxtFromConsole() {

//read inputs file
    try {
        List<String> lines = new ArrayList(); //list instance
        Scanner scanner = new Scanner(inputFile);

        //read the file line by line
        int lineNum = 0;
        while (scanner.hasNextLine()) {
            lines.add(scanner.nextLine()); //adding elements
            lineNum++;
        }

    return lines; //then return
    } catch (FileNotFoundException e) {


    }


  return null;

}

第二次编辑

如果你想获得循环返回列表所需的每个值;

  public void getCountByArea() {


    //always receive the same string
    List<String> inputToValidate = getInputsTxtFromConsole();
    List<String> inputToCompare = getInputsTxtFromConsole();


    for(String input1 : inputToValidate){ //input1 is a temp variable
        // your custom implementation
        ...
    }
    //another for each
    ...

}

如何在循环内返回

1 个答案: