Most unusual/weird syntax features in non-joke languages

Miscellaneous Topics
#21

I actually agree, wasn’t being serious :wink:

On topic: All LISPs qualify for this thread.

Cas :slight_smile:

#22

Javascript: [icode]undefined = 42;[/icode], which is why we all :persecutioncomplex: are forced to use [icode]if(typeof x === ‘undefined’)[/icode] as opposed to the more concise form: [icode]if(x === undefined)[/icode]

#23

I always thought the syntax for instantiating a non-static inner class from outside an instance of the outer class was weird:

public class Main {
	public static void main(String... args){
		new Main().new Inner().printMe();
	}
	
	private class Inner{
		public void printMe(){
			System.out.println("Inner class!");
		}
	}
}

For that matter, people tend to tilt their heads a bit sideways at using

main(String... args)

instead of

main(String[] args)

as well. I just think it looks cooler, and is arguably semantically closer to what’s happening under the hood!

#24

@KevinWorkman

Similarly, odd usages of this:

class Outer {
    class Inner {
        void foo() {
            Outer o = Outer.this;
        }
    }
}
#25

I’ve always loved this FORTH:

: ( 41 word drop ; immediate
( The previous defines comments )
#26 
	JFrame f = new JFrame() {{
				setTitle("Test");
				setSize(600, 600);
				add(new JButton() {{
						setText("Button");
						setBackground(Color.RED);
					}});
				setVisible(true);
			}};

Its not a syntax feature but an anonymous class using the anonymous class constructor thats weird…

-ClaasJG

#27

That’s called an initializer block. It’s covered in the basic tutorials here, but most people seem to skip over that part.

#28
#29

int [] a [];

17 years of Java, and I still had to check if that was actually valid syntax.

#30

Javascript:

‘’ == ‘0’ // false
0 == ‘’ // true
0 == ‘0’ // true
false == ‘false’ // false
false == ‘0’ // true
false == undefined // false
false == null // false
null == undefined // true
" \t\r\n" == 0 // true

More stuff: https://dorey.github.io/JavaScript-Equality-Table/

#31

MUMPS is essentially an exercise in horrifying language design, here’s some syntactical highlights:

[quote]CASE SENSITIVITY: Commands and intrinsic functions are case-insensitive. Variable names and labels are case-sensitive.

COMMANDS: may be abbreviated to one letter, case-insensitive. Includes commands such as IF, ELSE, GOTO, WRITE, and XECUTE [which is my personal favorite, it allows arbitrary execution of code contained in a variable]

OPERATORS: No precedence, executed left to right, parenthesize as desired. 2+3*10 yields 50.

DECLARATIONS: NONE. Everything dynamically created on first reference.

LINES: important syntactic entities. Multiple statements per line are idiomatic. Scope of IF and FOR is “remainder of current line.”
[/quote]
There’s also some nice non-lexical scoping type problems:

#32

Function pointers to member functions in C++ give you pretty weird syntax:

class Foo{
public:
    int f(string str){
    std::cout<<"Foo::f()"<<std::endl;
    return 1;
  }
};
 
int main(int argc, char* argv[]){
  int (Foo::*fptr) (string) = &Foo::f;
  Foo obj;
  (obj.*fptr)("str");//call: Foo::f() through an object
  Foo* p=&obj;
  (p->*fptr)("str");//call: Foo::f() through a pointer
}
#33

This is a Chrome problem, the language spec defines a result of “NaN” (Not A Number) which makes kind of sense … not really :wink:

#34

A friend of mine once snuck that into someone else’s code, then hurt himself laughing.

#35

This isn’t exactly strange syntax, but you can use reflection so that 2+2 equals 5:

import java.lang.reflect.Field;

public class Main {
    public static void main(String[] args) throws Exception {
        Class cache = Integer.class.getDeclaredClasses()[0];
        Field c = cache.getDeclaredField("cache");
        c.setAccessible(true);
        Integer[] array = (Integer[]) c.get(cache);
        array[132] = array[133];

        System.out.printf("%d",2 + 2);
    }
}

The above code outputs 5!

(Taken from here.)

#36

EDIT: ninja’d

If you think that’s funny, try hiding this somewhere in a static block:


Field value = Integer.class.getDeclaredField("value");
value.setAccessible(true);
value.set(1, 2); // or similar


System.out.println(Arrays.asList(0, 1, 2, 3));

[quote][0, 2, 2, 3]
[/quote]

#37

Ooops my apologies :frowning:

I posted about Javascript… but you were asking for “non-joke languages” :frowning:

#38

Java compared to Javascript is like Scrabble compared to Jenga… Very different, but both of them belong to the same category (programming languages and games) - first of them have very strict rules and requires some experience, second one gives more freedom and requires less learning, but - if you fail even slightly - it is over.