Question

代码在这里：

这是我目前的输出：

输出：

Integer Array Contents: 
, -3, 2, 0, 0, 1, -5
Total odd numbers: 3
Odd numbers are: -3 1 -5 0 0 0 
Index of last zero: 3
Minimum: -5
Maximum: 2
Sum: -5
Element mean is: 0.0
//1) How do I get rid of the random "," at the beginning? Lol 
//2) How do I get rid of the 0's that are in the "Odd numbers are: " category. 
//3) Mean's not working. What should I do to fix that. Maybe it has something to do     
//with the extra zeroes? I made it into a double and that didnt do anything either.

Answer 1

更简单的方法是利用Files#readAllLines将File的每一行读入List<Stirng>。然后，您可以使用String#join轻松地将每个String与逗号结合起来作为分隔符。

List<String> lines = Files.readAllLines(file.toPath());

String fileContents = String.join(",", lines);

如果您想返回true元素的总数，只需Stream List<String>并过滤掉等于true的元素，最后使用{ {1}}获取金额：

Stream#count

如果您想返回long numTrueElements = lines.stream().filter(s -> s.equals("true")).count();元素的总数，只需从false行的大小中减去true个元素的总数。

List<Stirng>

如果您想要第一个int numFalseElements = lines.size() - numTrueElements;元素的索引，那么您可以使用true：

List#indexOf

使用此方法，您可以完全抛弃int firstTrueIndex = lines.indexOf("true");和任何循环。

Answer 2

您可以使用System.out.print代替逗号：

int trues = 0;
int falses = 0;
int firstindex = -1;//first index init with -1 to check with it later
String del = "";
int i = 0;
while (scan.hasNextLine()) {
    String line = scan.next();
    if (line.equals("true")) {//if the line equal true then trues++;
        if (firstindex == -1) {//if the first index == -1 then assign 
                               //it to i number of words
            firstindex = i;
        }
        trues++;
    } else if (line.equals("false")) {//if the line equal false falses++
        falses++;
    }
    System.out.print(del + line);
    del = ",";
    i++;
}
System.out.println();
System.out.println("Total TRUEs: " + trues);
System.out.println("Total TRUEs: " + falses);
System.out.println("Index of first TRUE: " + 
                      (firstindex > -1 ? firstindex : "No true in file"));

(firstindex > -1 ? firstindex : "No true in file")表示如果输入== -1打印文件中不为，则打印索引

<强>输出

Welcome to the Info-Array Program!
Please enter the filename for the Boolean values: Boolean Array Contents: 
true,true,false,true,false,true
Total TRUEs: 4
Total TRUEs: 2
Index of first TRUE: 0

如何用逗号在一行上显示文件的输出？

3 个答案: