php js数组问题

<script type="text/javascript">
    var a = new Array();
    a = "a";
    a = "b";
    a = "c";
    a = "d";
//    alert(a[0])
    for(var i=0; i<a.length; i++){
        console.log(i + " " + a[i]);
    }
</script>

<?php
    $Cities[] = "<B>北京</B>";    //等同于$Cities[0] = "北京"
    $Cities[] = "<B>天津</B>";    //等同于$Cities[1] = "天津"
    $Cities[] = "<B>上海</B>";    //等同于$Cities[2] = "上海"
    $Cities[] = "<B>深圳</B>";    //等同于$Cities[3] = "深圳"
    /*
    ** 统计元素个数
    */
    $indexLimit = count($Cities);    //把数组中元素的个数赋给$indexLimit
    /*
    ** 打印所有数组
    */
    for($index=0; $index < $indexLimit; $index++)
    {
        print("第 $index 个城市是 $Cities[$index]。 <BR>\n");
    }
?>