import java.util.*; class Test { public static void main(String[] args) { Scanner sc = new Scanner(System.in); System.out.println("please input a float data[eg. 5.2f]:"); String data = sc.nextLine(); if (!data.matches("\\d+([.]\\d+)?[fF]?")){ System.out.println("error input"); } else { float f = Float.valueOf(data); System.out.printf("your input is %5.2f\n", f); } } }
System.out.printf("%.1ff\n", f);
String s = String.format("%.1ff", f);
System.out.println(s);
return String.format("%.1ff", f);
}public static void main(String args[]) {
float valF = 5.2f;
System.out.println(valF);
}
5.2f的意思是总共五位包括小数点,小数点后两位,float型
float a = 2.31f;
System.out.println(formater.format(a));
原来是要自己输入数字啊 那就看下面这个代码 楼上那个代码输入整数出来还是整数的 String money ="24";//你要传入的数
float a = 0.0f;
DecimalFormat formater = new DecimalFormat("#0.## ");
if(money!=null&&!"".equals(money)){
if(!money.contains(".")){
money = money+".00";
}else{
a=Float.valueOf(money);
money = formater.format(a);
}
}
System.out.println(money);
}
class Test {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println("please input a float data[eg. 5.2f]:");
String data = sc.nextLine();
if (!data.matches("\\d+([.]\\d+)?[fF]?")){
System.out.println("error input");
} else {
float f = Float.valueOf(data);
System.out.printf("your input is %5.2f\n", f);
}
}
}