Extracting Float values from a string in Java

Question

I have a string like this "Humidity: 14.00% Temperature:28.00 C".

I want to extract the two float values from the string, how can I do so?

Answer 1

First, take a look at @Bathsheba`s comment.
I have a straightforward way, but that is not clever or universal.

String[] array = string.replaceAll("[Humidity:|Temperature:|C]", "").split("%");

You will receive String[]{"14.00", "28.00"} and then you may convert these values of the array into Float by using Float.parse() or Float.valueOf() methods.

Arrays.stream(array).map(Float::valueOf).toArray(Float[]::new);

Answer 2

You can try this, using regex

String regex="([0-9]+[.][0-9]+)";
String input= "Humidity: 14.00% Temperature:28.00 C";

Pattern pattern=Pattern.compile(regex);
Matcher matcher=pattern.matcher(input);

while(matcher.find())
{
    System.out.println(matcher.group());
}

Answer 3

(Disclaimer : You should look at @Andrew Tobilko' s answer if you want some much cleaner and reusable code).

First you need to separate your string into two substrings. You can do this using String a = yourString.substring(10,14); String b =yourString.substring(29,33);

Then, you use Float.parseFloat(String s) to extract a float from your strings :

Float c=Float.parseFloat(a); Float d= Float.parseFloat(b);

That is if your String is exactly the one that you wrote. Otherwise, you should make sure that you use the right indexes when you call String.substring(int beginIndex, int endIndex).