public class LeadingZerosExample {
public static void main(String[] args) {
int number = 1500;
// String format below will add leading zeros (the %0 syntax)
// to the number above.
// The length of the formatted string will be 7 characters.
String formatted = String.format("%07d", number);
System.out.println("Number with leading zeros: " + formatted);
}
}
public class LeadingZerosExample {
public static void main(String[] args) {
int number = 1500;
// String format below will add leading zeros (the %0 syntax)
// to the number above.
// The length of the formatted string will be 7 characters.
String formatted = String.format("%07d", number);
System.out.println("Number with leading zeros: " + formatted);
}
}
In case you have to do it without the help of a library:
("00000000" + "Apple").substring("Apple".length())
(Works, as long as your String isn't longer than 8 chars.)
How to format strings in Java - Stack Overflow
Java String Format: "%0" and "d%s" - Stack Overflow
How to format a number starts with zero.
Add leading zeroes to number in Java? - Stack Overflow
Videos
Take a look at String.format. Note, however, that it takes format specifiers similar to those of C's printf family of functions -- for example:
String.format("Hello %s, %d", "world", 42);
…would return "Hello world, 42". The "format string" link points to the complete official spec, but for simple cases, this much shorter documentation may be helpful for an introduction to format specifiers even though it's outdated and about Lava. The most commonly used ones are:
- %s - insert a string
- %d - insert a signed integer (decimal)
- %f - insert a real number, standard notation
This is radically different from C#, which uses positional references with an optional format specifier. That means that you can't do things like:
String.format("The {0} is repeated again: {0}", "word");
... without actually repeating the parameter passed to printf/format. (see The Scrum Meister's comment below)
If you just want to print the result directly, you may find System.out.printf (PrintStream.printf) to your liking.
In addition to String.format, also take a look java.text.MessageFormat. The format less terse and a bit closer to the C# example you've provided and you can use it for parsing as well.
For example:
int someNumber = 42;
String someString = "foobar";
Object[] args = {new Long(someNumber), someString};
MessageFormat fmt = new MessageFormat("String is \"{1}\", number is {0}.");
System.out.println(fmt.format(args));
A nicer example takes advantage of the varargs and autoboxing improvements in Java 1.5 and turns the above into a one-liner:
MessageFormat.format("String is \"{1}\", number is {0}.", 42, "foobar");
MessageFormat is a little bit nicer for doing i18nized plurals with the choice modifier. To specify a message that correctly uses the singular form when a variable is 1 and plural otherwise, you can do something like this:
String formatString = "there were {0} {0,choice,0#objects|1#object|1<objects}";
MessageFormat fmt = new MessageFormat(formatString);
fmt.format(new Object[] { new Long(numberOfObjects) });
Hello, so I have a question to check whether a number is a palindrome or not, (a palindrome is a number that you read the same if you read it digit by digit from left to right or vice versa). keeping in mind you must enter only 5 digits, However I don't know how to deal with it if the user enters 0 for example 02120 is palindrome, however, java omit the first zero so it's considered as a non palindrome.
Here is what I managed to so so far but it doesn't work with numbers starting with 0 .
thank you.
String.format (https://docs.oracle.com/javase/1.5.0/docs/api/java/util/Formatter.html#syntax)
In your case it will be:
String formatted = String.format("%03d", num);
- 0 - to pad with zeros
- 3 - to set width to 3
Since Java 1.5 you can use the String.format method. For example, to do the same thing as your example:
String format = String.format("%0%d", digits);
String result = String.format(format, num);
return result;
In this case, you're creating the format string using the width specified in digits, then applying it directly to the number. The format for this example is converted as follows:
%% --> %
0 --> 0
%d --> <value of digits>
d --> d
So if digits is equal to 5, the format string becomes %05d which specifies an integer with a width of 5 printing leading zeroes. See the java docs for String.format for more information on the conversion specifiers.