Iteration through object hash

test.js

var keys = [],
    attrs = {},
    c = [];

for( var i = 0; i < 20; i++ ){
    keys.push( 'a' + i );
    attrs[ 'a' + i ] = i;
    c.push( 'a.a' + i + '=== void 0 || f( a.a' + i + ');')
}

function Obj(){
    this.a1 = 0;
    this.a2 = 0;
    this.a3 = 0;
    this.a4 = 0;
    this.a5 = 0;
    this.a6 = 0;
    this.a7 = 0;
    this.a8 = 0;
    this.a9 = 0;
    this.a10 = 0;
    this.a11 = 0;
    this.a12 = 0;
    this.a13 = 0;
    this.a14 = 0;
    this.a15 = 0;
    this.a16 = 0;
    this.a17 = 0;
    this.a18 = 0;
    this.a19 = 0;
    this.a20 = 0;
}

var objAttrs = new Obj();

var compiled = new Function( 'a', 'f', c.join( '' ) );

function testC(){
    var count = 0;

    compiled( attrs, function( val ){ count+= val });
}

function testLoop(){
    var count = 0;

    for( var i = 0; i < keys.length; i++ ){
        var name = keys[ i ],
            val = attrs[ name ];

        if( val !== void 0 ){
            count += val;    
        }
    }
}

function testHash(){
    var count = 0;

    for( var name in attrs ){
        count += attrs[ name ];    
    }
}

function testObj(){
    var count = 0;

    for( var name in objAttrs ){
        count += objAttrs[ name ];    
    }
}

function measure( fun, count ){
    var start = window.performance.now();

    for( var i = 0; i < count; i++ ){
        fun();
    }

    console.log( window.performance.now() - start );    
}

console.log( "Hash loop:" );
measure( testHash, 1000000 );

console.log( "Class loop:" );
measure( testObj, 1000000 );

console.log( "Array loop:" );
measure( testLoop, 1000000 );

console.log( "Unrolled loop:" );
measure( testC, 1000000 );