想要为每个循环在Java中解决这个简单的问题

Question

 for (float f: values)
    {
        int a=(int) (f*255);
        builder.append(' ')
               .append(a+",");
    }

values is array of float type builder is StringBuilder type on every call I have 3 float values in values array I am trying to append 'a' to builder and ',' here what I am getting is like (255,145,234,) but what I want is like this(255,145,234) I want to omit the last comma your Help is quite helpful to me Thanks.

Answer 1

Try this:

String delimiter = "";
for (float f: values)
    {
        builder.append(delimiter)
        delimiter = ", ";
        int a=(int) (f*255);
        builder.append(a);
    }

Alternatively, simply chop off the last character from the StringBuilder after the loop exits:

builder.setLength(builder.length() - 1);

Answer 2

Maintain a count , and append "," until count is less than length of array.

public static void main(String[] args) {

        float[] values = { 255, 145, 234 };
        StringBuilder builder = new StringBuilder();
        int count = 0;

        for (float f : values) {
            count++;
            int a = (int) (f * 255);
            builder.append(' ').append(a);
            if (count < values.length) {
                builder.append(",");
            }
        }
        System.out.println(builder.toString());
    }

output

 65025, 36975, 59670

Answer 3

Use this. But there is no use of StringBuilder here..

    ArrayList<String> val = new ArrayList<>();
    for(float f: values){
        val.add((int)(f*255)+"");
    }
    String s = String.join(", ", val);
    System.out.println(s);