var isNumber = require("is-number");
var slice = require("array-slice");
// n can be integer, double, string like "1.2","abc",object, null, undefined..
module.exports=function(arr,n){
    if(!Array.isArray(arr))
        throw new TypeError("Expect array, but got "+typeof arr);
    if(arr.length==0 || n==0) return null;
    n=isNumber(n)?+n:1;//+n: "1.2"=>1.2
    if(!n||n==1) return arr[0];//just return a scalar
    var res= slice(arr,0,n); //if n>1, return an array
    return res;
}