Parsing an array of comma-numbers obtained from an input dialog

Question

I made this nice bit of code that I can insert into any of my projects requiring user input. It seems quite long for what it does and I would love some incite as to how I can do this more efficiently i.e. fewer lines of code.

I love to make my code elegant, but I don't see how to do it any better.

 String x = (JOptionPane.showInputDialog(". Each patamater should be separated with a ',' and without spaces. (eg. 1,2,3)") + ",");
 int w = 0, a = 0, y = -1;
 for(int i = 0; i < x.length(); i++)
 {
 if(x.charAt(i) == ',')
 {
 w++;
 }
 }
 Double[] z = new Double[w];
 for(int i = 0; i < x.length(); i++)
 {
 if(x.charAt(i) == ',')
 {
 z[a] = Double.parseDouble(x.substring((y + 1), i));
 y = i;
 a++;
 }
 }

• Pazis: Fewer lines of code does not mean that your program is more efficient.
• lukeb28: @Pazis: Whats the distinction?
• sdasdadas: @lukeb28 Calling a function like orderEveryDogInTheWorld(); will take more time than calling int x = 0; and x = x + 1;, even though the second example is two lines.

Answer 1

I suggest next way:

 String x = (JOptionPane.showInputDialog(". Each patamater should be separated with a ',' and without spaces. (eg. 1,2,3)") + ",");
 String[] split = x.split(",");
 Double[] z = new Double[split.length];
 int i = 0;
 for (String s : split) {
 if(s.trim().isEmpty()){
 continue;
 }
 try {
 z[i++] = Double.valueOf(s.trim());
 } catch (NumberFormatException e) {
 e.printStackTrace();
 }
 }

1)split() instead of loop for ','

2)validate spaces

read more about String class and it's functions.

• lukeb28: I've never seen split, s.trim, or .isEmpty. Would you mind running through how these functions work? I prefer comprehension to memorization.
• sdasdadas: @lukeb28 It will sink in more (requiring less memorization) if you hunt for them in the docs.