CODEWITHSUNDEEP
javastringdouble
franklin
franklin

Reputation: 1819

list of strings to list of doubles java

I have a data file containing a combination of doubles and strings like this:

Rmax=2.3
Rmin=1.0

etc.

I'm using split() to cut out the = like this:

while ((strLine = br.readLine()) != null) {
            String phrase = strLine;                
            try {
                //splits to variable name, value
                String[] parsed = phrase.split("[=]");                      
                int parsed[0].toString() = parsed[1];

            } catch (PatternSyntaxException e) {
                System.out.println("Error: " + e.getMessage());
            }
        }

Now i'm trying to get the values initialized so that parsed[0] becomes the name of the integer and parsed[1] becomes the value. equivalent to the initializer int name = value;

obviously the line 

int parsed[0].toString() = parsed[1];

doesn't work. how do i go about doing this?

Upvotes: 1

Views: 2661

Answers (4)

Peter Lawrey
Peter Lawrey

Reputation: 533442

How about this

Map<String, Double> map = new HashMap<String,Double>()
while ((strLine = br.readLine()) != null) {
    //splits to variable name, value
    String[] parsed = phrase.split("=");
    String name = parsed[0];
    double value = Double.parseDouble(parsed[1]);
    map.put(name, value);
}

As has been mentioned you have to catch NumberFormatException and handle a missing '=' depending on whether these are possible.

If you know all possible fields you could use an enum for the field name.

Instead of using a Map you could use an Object which you set via reflection.

class Config {
    double Rmax;
    double Rmin;
    // add more fields here.
}

Config config = new Config;
    while ((strLine = br.readLine()) != null) {
    //splits to variable name, value
    String[] parsed = phrase.split("=");
    try {
       String name = parsed[0];
       double value = Double.parseDouble(parsed[1]);
       Config.class.getField(name).setDouble(value);
    } catch (Exception e) {
       // log exception.
    }
}

Upvotes: 3

Sean Patrick Floyd
Sean Patrick Floyd

Reputation: 298818

You can read it to a Properties object and do the conversion from there:

Properties props = new Properties();
props.load( /* your file as InputStream */ );
Map<String, Double> parsed = new HashMap<String, Double>();
for(Map.Entry<Object, Object> entry : props.entrySet()){
    parsed.put(entry.getKey().toString(),
    Double.valueOf(entry.getValue().toString());
}

Upvotes: 2

Peter Zeller
Peter Zeller

Reputation: 2276

Maybe you want something like this:

  String theName = parsed[0];
  double theValue = Double.parseDouble(parsed[1]);

Upvotes: 1

RMT
RMT

Reputation: 7070

Why not use a HashMap

With a hash map you can set Key value with what ever types you want. In this case you want

HashMap<String, Double> map = new HashMap<String,Double>()

Upvotes: 2

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