如何把这段Java代码转换为JavaScript代码？？

Question

<script>
function transDisplay(str){
return str.replace(/ /g,"&nbsp;").replace(/</g,"&lt;").replace(/>/g,"&gt;").replace(/\n/g,"<br>").replace(/"/g,"&quot;").replace(/&(?!#)/g,"&amp;").replace(/\t/g,"&nbsp;&nbsp;&nbsp;&nbsp;")
}
alert(transDisplay('&#12;return str.replace(/ /g,"&nbsp;").replace(/</g,"&lt;").replace(/>/g,"&gt;").replace(/\n/g,"<br>").replace(/"/g,"&quot;").replace(/&(?!#)/g,"&amp;").replace(/\t/g,"&nbsp;&nbsp;&nbsp;&nbsp;")'));
</script>