var wi = 0; wi < arr.length; wi++

思维

<?php
$w = 123;
$wb = $w;

$w = 456;

echo $wb;

?>

<script type="text/javascript">
    var w = 123;
    var wb = w;
    w = 456;
    alert(wb);

var arr = [14, 23, 100, 4, 58, 7, 7, 8, 7, 14, 14, 58, 2, 5, 5, 5, 11, 4];

var arrb = arr;
                console.log(arrb);
arr = [123];
    console.log(arrb);
    ;

</script>

去重复 奇数偶数