Why does obXX[0] below in openprocessing not cause an error?

Processing Beginners
1

Run this

void setup(){
all = new obXX[0];
}

here in Chrome.

Expected: Error.

Observed: No error. Why?

PS all = new obXX; gives a ReferenceError as expected.

2

My guess – and I defer to Processing.js experts like @GoToLoop on this – is that this is because openprocessing uses Processing.js, and Processing.js is not bothering to enforce correctness in Java syntax when it compiles to JavaScript – instead, it is assuming that you are writing hybrid Java / Javascript, and attempting to interpret it as valid.

http://processingjs.org/articles/jsQuickStart.html#javascriptonlyprocessingcode

So, if you inspect your example using the code helper:

http://processingjs.org/tools/processing-helper.html

…you can see that the compiler has created an array and assigned it to “all”

// this code was autogenerated from PJS
(function($p) {
    function setup() {
        all = $p.createJavaArray('obXX', [0]);
    }
    $p.setup = setup;
    setup = setup.bind($p);
})

The section “Writing Documents that Combine Processing and JavaScript Code” seems like it might explain what is happening with that output.