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javastring-formattingnumber-formatting

Format an Integer using Java String Format

I am wondering if it is possible, using the String.format method in Java, to give an integer preceding zeros?

For example:

1 would become 001
2 would become 002
...
11 would become 011
12 would become 012
...
526 would remain as 526
...etc

At the moment I have tried the following code:

String imageName = "_%3d" + "_%s";

for( int i = 0; i < 1000; i++ ){
    System.out.println( String.format( imageName, i, "foo" ) );
}

Unfortunately, this precedes the number with 3 empty spaces. Is it possible to precede the number with zeros instead?

Solution

  • Use %03d in the format specifier for the integer. The 0 means that the number will be zero-filled if it is less than three (in this case) digits.

    See the Formatter docs for other modifiers.