How can I pad an integer with zeros on the left?

Question

How do you left pad an int with zeros when converting to a String in java?

I\'m basically looking to pad out integers up to 9999

Answer 1

No packages needed:

String paddedString = i < 100 ? i < 10 ? "00" + i : "0" + i : "" + i;

This will pad the string to three characters, and it is easy to add a part more for four or five. I know this is not the perfect solution in any way (especially if you want a large padded string), but I like it.

Answer 2

Try this one:

import java.text.DecimalFormat; 

DecimalFormat df = new DecimalFormat("0000");

String c = df.format(9);   // Output: 0009

String a = df.format(99);  // Output: 0099

String b = df.format(999); // Output: 0999

Answer 3

Use the class DecimalFormat, like so:

NumberFormat formatter = new DecimalFormat("0000"); //i use 4 Zero but you can also another number
System.out.println("OUTPUT : "+formatter.format(811)); 

OUTPUT : 0000811

Answer 4

You need to use a Formatter, following code uses NumberFormat

    int inputNo = 1;
    NumberFormat nf = NumberFormat.getInstance();
    nf.setMaximumIntegerDigits(4);
    nf.setMinimumIntegerDigits(4);
    nf.setGroupingUsed(false);

    System.out.println("Formatted Integer : " + nf.format(inputNo));

Output: 0001

Answer 5

int x = 1;
System.out.format("%05d",x);

if you want to print the formatted text directly onto the screen.

Answer 6

Use java.lang.String.format(String,Object...) like this:

String.format("%05d", yournumber);

for zero-padding with a length of 5. For hexadecimal output replace the d with an x as in "%05x".

The full formatting options are documented as part of java.util.Formatter.