使用 java 中的 Stream 将列表字符串转换为 ArrayList 浮点数

Question

Good afternoon, Community!

I have a List:

List<String> rate = new ArrayList<>(); 

and I need to convert the data into a float if it can be done with java 8 stream. I was doing it in the following way:

float valueRate = Float.parseFloat(rate);

Answer 1

Try it like this:

• Given a list of strings floating point values.
• map them to a stream of float using Float.valueOf()
• and collect into a List.

List<String> list = List.of("1.2", "3.4", "2.5f");
List<Float> floats = list.stream().map(Float::valueOf).collect(Collectors.toList());
    
System.out.println(floats);

Prints

[1.2, 3.4, 2.5]

Answer 2

You can use Stream#map with Float.valueOf (to avoid autoboxing).

List<Float> res = rate.stream().map(Float::valueOf).collect(Collectors.toList());

With Java 16:

List<Float> res = rate.stream().map(Float::valueOf).toList();