Convert a string into a decimal number with 2 decimal places in Java

In Java, I try to parse a string of formats "####. ##" into floating point numbers The string should always have 2 decimal places

Even if the value of string is 123.00, the floating-point number should be 123.00 instead of 123.0

This is what I have done so far:

System.out.println("string liters of petrol putting in preferences is " + stringLitersOfPetrol);

Float litersOfPetrol = Float.parseFloat(stringLitersOfPetrol);

DecimalFormat df = new DecimalFormat("0.00");
df.setMaximumFractionDigits(2);

litersOfPetrol = Float.parseFloat(df.format(litersOfPetrol));

System.out.println("liters of petrol before putting in editor: " + litersOfPetrol);

It prints:

string liters of petrol putting in preferences is 010.00 
liters of petrol before putting in editor: 10.0

Solution

This is your problem:

litersOfPetrol = Float.parseFloat(df.format(litersOfPetrol));

There you format your float as a string as needed, but then the string is converted to a floating point number again, and then you print your floating point number in stdout to get the standard format Look at this code

import java.text.DecimalFormat;

String stringLitersOfPetrol = "123.00";
System.out.println("string liters of petrol putting in preferences is "+stringLitersOfPetrol);
Float litersOfPetrol=Float.parseFloat(stringLitersOfPetrol);
DecimalFormat df = new DecimalFormat("0.00");
df.setMaximumFractionDigits(2);
stringLitersOfPetrol = df.format(litersOfPetrol);
System.out.println("liters of petrol before putting in editor : "+stringLitersOfPetrol);

By the way, when you want to use decimals, forget the existence of double and float. As others suggest, using only BigDecimal objects will save you a lot of trouble