Flatten Array

This quick function takes a an array, whose elements may or may not be other arrays, and flattens it into a single array.

Extremely simple solution, but kind of fun because it's a chance to use recursion:

<script type=text/javascript>
var a = [1,2,[5,6,7], 8, [9,10,[11,12],13], 14];

function flatten( oArray ) {
var retVal = [];
for (var i=0;i<oArray.length;i++) {
if (!isArray( oArray[i]) ) {
retVal.push( oArray[i] );
} else {
var tempFlatt = flatten(oArray[i]);
for (var j=0;j<tempFlatt.length;j++) {
retVal.push( tempFlatt[j] );
}
}
}
return retVal;
}

function isArray( anElement ) {
return (typeof anElement=="object" && anElement.constructor == Array);
}

alert(flatten(a));
</script>