1、结果保留一位小数:
float a = (float) 15.3;
float b = (float) 18.6;
DecimalFormat df = new DecimalFormat("##0.0"); //结果保留一位小数
if(a >= b){
System.out.println("a大"+df.format(a-b));
}else{
System.out.println("b大"+df.format(b-a));
}
结果:b大3.3
2、结果不保留
float a = (float) 15.3;
float b = (float) 18.6;
DecimalFormat df = new DecimalFormat("##0.0"); //结果保留一位小数
if(a >= b){
System.out.println("a大"+(a-b));
}else{
System.out.println("b大"+(b-a));
}
结果:b大3.3000002