格式化小數點和百分號 DecimalFormatter

1.

public class DecimalFormatterTest {
    public static void main(String[] args) {
      //DecimalFormat df = new DecimalFormat("0.00#"); //兩個構造器
        DecimalFormat decimalFormat = new DecimalFormat();

        decimalFormat.applyPattern(".###");
        System.out.println(decimalFormat.format(23.112));//23.112
        System.out.println(decimalFormat.format(0.112));//.112

        decimalFormat.applyPattern("0.00#");//推薦
        System.out.println(decimalFormat.format(23.112));//23.112
        System.out.println(decimalFormat.format(0.112));//0.112

        decimalFormat.applyPattern("0.00%");//推薦
        System.out.println(decimalFormat.format(23.112));//2311.20%
        System.out.println(decimalFormat.format(0.112));//11.20%
        System.out.println(decimalFormat.format(0.2345));//23.45%

        decimalFormat.applyPattern(".##%");
        System.out.println(decimalFormat.format(23.112));//2311.2%
        System.out.println(decimalFormat.format(0.112));//11.2%
        System.out.println(decimalFormat.format(0.2345));//23.45%

    }
}