Shortest code to throw IllegalArgumentException in Java

Question

Okey, we all know the normal way to throw a IllegalArgumentException in Java:

throw new IllegalArgumentException(); // 37 characters

But there must be a shorter (as in less characters) ways to do so. How can we produce a java.lang.IllegalArgumentException with even less code?

• The code fragment has to compile and run in java 7.
• No imports/external packages (e.g. not using java.util.Arrays.toString() )
  • only exception: java.lang because it is automatically imported.
• You can add own methods/classes.
• It must throw a java.lang.IllegalArgumentException
  • Edit: the error output (stacktrace) must name it java.lang.IllegalArgumentException, so no subclasses of it.

To have a base to start from:

class Titled {
    public static void main(String[] args) {
        throw new IllegalArgumentException();
    }
}

Answer 1

These were all found by grepping the source code in the package java.lang.

All of them result in a "pure" IllegalArgumentException (i.e. not a subclass of it).

The ones marked * only work if you add " throws Exception" (18 characters) to your main declaration, as they throw a checked exception of some kind.

12 (30?) characters*

"".wait(-1);

This will result in:

java.lang.IllegalArgumentException: timeout value is negative

22 (40?) characters*

new Thread().join(-1);

22 characters

Character.toChars(-1);

30 characters

Character.UnicodeBlock.of(-1);

Answer 2

Here's a nice short way to do it, in 17 13 chars:

new Long("");

It throws a NumberFormatException, which is an IllegalArgumentException. This and this verify it.

Equivalently, one could do

new Byte("");

Answer 3

22 characters:

Character.toChars(-1);

Running example
Javadoc: java.lang.Character.toChars(int)

Some nice looking variants:

Character.toChars(~4); // 22 characters, number can be any non-negative (and -0)

Character.toChars(1<<7); // 24 characters

~i is the same as -1 * (i+1) because it inverts the bits. So we will get a illegal parameter, because it is smaller then 0.
1<<7 will create a too high number by shifting the 1 seven times. (same as multiply it 7 times with 2). The last accepted Value seems to be 1114111, 1114112 will fail. Note: this might change depending on your environment, and could be not always reliable.

See the Oracle Docs "Bitwise and Bit Shift Operators" and "Primitive Data Types"

28 characters:

And if you don't like using the character class in a character count competition*:

Enum.valueOf(Enum.class,""); // 28 characters

*) Just to make this pun.

Answer 4

21 characters:

System.getProperty("");

As per the documentation, getProperty and setProperty throw IllegalArgumentException if the key is empty.

Answer 5

25 Characters

Creates a vector with an invalid (negative) length:

new java.util.Vector(-1);

Displays:

Exception in thread "main" java.lang.IllegalArgumentException: Illegal Capacity: -1
    at java.util.Vector.<init>(Vector.java:129)
    at java.util.Vector.<init>(Vector.java:144)
    at Titled.main(Titled.java:3)

Answer 6

Here's 24 characters:

System.out.printf("%z");

This will throw an IllegalFormatException, which is an IllegalArgumentException.

Answer 7

19 characters:

String.format("%");

Throws java.util.UnknownFormatConversionException, which inherits from IllegalFormatException, which, in turn, inherits from IllegalArgumentException;

Answer 8

14 Characters

this.wait(-1);

17 Characters

Thread.sleep(-1);

As far as code that directly throws IllegalArgumentException, these will do it.

From documentation: 
Thread.sleep(int millis): 
Throws:IllegalArgumentException - if the value of millis is negative
InterruptedException - if any thread has interrupted the current thread. 

so direct code is 17 chars, if you're being a super stickler and counting the chars to add a throws clause for the interupted exception you can shorten it by just throwing the raw Exception class