在Java中使用扫描仪忽略字符 [英] Ignoring characters using Scanner in Java

问题描述

我想从标准输入中获取多个坐标点，例如(35，-21)(55,12)...，并将它们放入各自的数组中.

I want to take a multiple coordinate points, say (35,-21) (55,12)... from standard input and put them into respective arrays.

我们称它们为x []和y [].

Let's call them x[] and y[].

x []将包含{35，55，...}，而y []将包含{-21，12，...}，依此类推.

x[] would contain {35, 55, ...} and y[] would contain {-21, 12, ...} and so forth.

但是，我似乎找不到解决括号和逗号的方法.

However, I can't seem to find a way to get around the parenthesis and commas.

在c中，我使用了以下内容:

In c I was using the following:

for(i = 0; i < SIZE; i++) {
    scanf("%*c%d%*c%d%*c%*c",&x[i],&y[i]);
}

但是，在Java中，我似乎找不到解决非数字字符的方法.

However in Java I can not seem to find a way to get around the non-numeric characters.

由于受困，我目前在Java中拥有以下内容.

I currently have the following in Java, as I am stuck.

double[] x = new double[SIZE];
double[] y = new double[SIZE];
Scanner sc = new Scanner(System.in);

for(int i=0; i < SIZE; i++) {
    x[i] = sc.nextDouble();
}

所以问题是: 从扫描仪读取双打时，我将如何忽略字符?

So the question: How would I ignore characters when reading in doubles from scanner?

快速

A quick edit:

我的目标是在用户输入上保留严格的语法(12，-55)，并能够输入多行坐标点，例如:

My goal is to keep the strict syntax (12,-55) on user input, and being able to enter multiple rows of coordinate points such as:

(1,1) (2,2) (3,3) ...

(1,1) (2,2) (3,3) ...

推荐答案

我将分多个步骤进行操作，以提高可读性.首先是System.in，它使用扫描仪进行检索，然后进行拆分以分别获取每组坐标，然后可以出于任何目的稍后对其进行处理.

I would do it in multiple steps for improved readability. First it's the System.in retrieving using a scanner and then you split in order to get each group of coordinates separately and then you can work on them later, for whatever purposes.

类似的东西:

Scanner sc = new Scanner(System.in);
String myLine = sc.nextLine();

String[] coordinates = myLine.split(" ");
//This assumes you have a whitespace only in between coordinates 

String[] coordArray = new String[2];
double x[] = new double[5];
double y[] = new double[5];
String coord;

for(int i = 0; i < coordinates.length; i++)
{
  coord = coordinates[i];
  // Replacing all non relevant characters
  coord = coord.replaceAll(" ", "");
  coord = coord.replaceAll("\\(", ""); // The \ are meant for escaping parenthesis
  coord = coord.replaceAll("\\)", "");
  // Resplitting to isolate each double (assuming your double is 25.12 and not 25,12 because otherwise it's splitting with the comma)
  coordArray = coord.split(",");
  // Storing into their respective arrays
  x[i] = Double.parseDouble(coordArray[0]);
  y[i] = Double.parseDouble(coordArray[1]);
}

请记住，这是一个基本解决方案，假定严格遵守输入字符串的格式.

Keep in mind that this is a basic solution assuming the format of the input string is strictly respected.

请注意，我实际上无法完全对其进行测试，但应该只保留一些简便的解决方法.

Note that I actually cannot fully test it but there should remain only some light workarounds.

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