Internet Explorer, Closure Compiler and Trailing Commas

Question

I\'m using html5boilerplate build script and when minifying the scripts (which uses Google Closure Compiler)

I\'m getting this error

-js.all.minify:         


        

Answer 1

Remove the superfluous last comma from your object literal:

anim1.animate({
    'left': '+=32px',
    'filter': 'alpha(opacity=100)',
    '-moz-opacity': '1',
    '-khtml-opacity': '1',
    'opacity': '1'      // <-- No comma here.
}, { duration: 727 });  // <-- I'd also suggest a semicolon there.

As the Closure compiler says, literals with such trailing commas cannot be parsed by some browsers.

Answer 2

Or enable EcmaScript 5 mode. Ecmascript 5 does standardize the trailing comma behavior but IE8 does not fully support it ES5 (neither does IE9 which is missing strict mode).