方法一：

<script>
var arr = ['abc','abcd','sss','2','d','t','2','ss','f','22','d'];

//定义一个新的数组

var s = [];

//遍历数组

for(var i = 0;i<arr.length;i++){

    if(s.indexOf(arr[i]) == -1){  //判断在s数组中是否存在，不存在则push到s数组中

        s.push(arr[i]);

    }

}

console.log(s);

//输出结果：["abc", "abcd", "sss", "2", "d", "t", "ss", "f", "22"]


</script>