如何确定从Java中的文本文件读入的最大值和最小值

Question

我正在上课的作业，正在寻找一些有用的指示，而不是完整的解决方案。基本上，我必须编写一个Java程序，该程序读取一个文本文件并逐行列出信息，列出行号，最后打印出最大值和最小值以及与每个值相关的年份。文本文件包含一年和该年的温度。因此，它列出了类似“
1900
50.9”的内容。我不是要使用数组或扫描仪，这是分配的一部分。我已经能够成功地使程序逐行打印并逐行打印出相应的温度。有人告诉我，我确实使用了while循环。现在，我唯一的问题是以某种方式可以区分所有温度的方式访问文本文件，最大值和最小值，以及每个年份发生的年份。到目前为止，我一直没有寻求帮助，因为我希望自己自行解决，但这项工作不再值得任何功劳到后期罚款。任何帮助将不胜感激，因为我仍然想解决这个问题。谢谢。

这就是我所拥有的。

public class main {

/**
 * @param args the command line arguments
 */

public static void main(String[] args) throws Exception {


File temps = new File ("temps.txt"); //Creates path to temps.txt file
FileReader textReader = new FileReader (temps); //Input information from temps.txt file into file reader
BufferedReader kb = new BufferedReader (textReader); //Use buffered reader to hold temps.txt file info from the file reader




String tempList; //Create string variable named tempList
int lineCount = 0; //Create integer variable named lineCount
String sep = ": Temp "; //Create string variable named sep (short for separation) and set it equal to the literal string ":"
String space = " "; //Create string variable named space and set it equal to an actual space between texts


System.out.println("The following is the provided information from the file input. ");
while ((tempList = kb.readLine()) !=null) { //while loop stating that as long as the text file still has values to read (is not null), continue to execute


    System.out.println("Line " + lineCount++ + ": Year " + tempList.replace(space, sep)); //Prints out the line number (lineCount++), the info from the temps.txt file with a ":" between the year and the number (tempList.replace (space,sep)

}




}

}

到目前为止的输出是这样的：

Line 0: Year 1900: Temp 50.9
Line 1: Year 1901: Temp 49
Line 2: Year 1902: Temp 49.7
Line 3: Year 1903: Temp 49.5
Line 4: Year 1904: Temp 47.1
Line 5: Year 1905: Temp 49.1

等等…

Line 99: Year 1999: Temp 52.7
BUILD SUCCESSFUL (total time: 0 seconds)

Answer 1

这是一种实现html" target="_blank">方法：

String tempList; //Create string variable named tempList
int lineCount = 0; //Create integer variable named lineCount
String sep = ": Temp "; //Create string variable named sep (short for separation) and set it equal to the literal string ":"
String space = " "; //Create string variable named space and set it equal to an actual space between texts

String maxValueYear = "";
String minValueYear = "";
double maxValue = 0;
double minValue = Double.MAX_VALUE;
System.out.println("The following is the provided information from the file input. ");
while ((tempList = kb.readLine()) !=null) { //while loop stating that as long as the text file still has values to read (is not null), continue to execute

    String year = tempList.substring(0, tempList.indexOf(space));
    double temp = Double.valueOf(tempList.substring(tempList.indexOf(space), tempList.length()));

    if (temp > maxValue) {
        maxValue = temp;
        maxValueYear = year;
    }
    if (temp < minValue) {
        minValue = temp;
        minValueYear = year;
    }
    System.out.println("Line " + lineCount++ + ": Year " + tempList.replace(space, sep)); //Prints out the line number (lineCount++), the info from the temps.txt file with a ":" between the year and the number (tempList.replace (space,sep)

}

System.out.println("The minimum temp occured in year " + minValueYear + " and was " + minValue);
System.out.println("The maximum temp occured in year " + maxValueYear + " and was " + maxValue);