数组去重

    <script>
        var arr = [ 1, 1, 1, 2, 2, 2, 3, 3, 4, 4, 4, 4, 5, 6 , 6, 6, 7, 7, 7, 7 ,8, 8, 8, 8, 8, 9, 9,9];


        var newarr = [];


        for ( var i = 0; i < arr.length; i++ ) {
            if ( newarr.indexOf( arr[ i ] ) == -1 ) {
                newarr.push( arr[ i ] );
            }
        }


        console.log( newarr );
    
    
    </script>