"use strict"

function isNumeric(n) {     //checking for a number.
  return !isNaN(parseFloat(n)) && isFinite(n);
}


function setArray(n) {  //set an array of "n" random elements.
    if (isNumeric(n) == false) {
        alert("Not a number!");
    }
    else if (n > 0) {
        var arr = [];
        while(n) {
            for(var i = 0; i < n; i++) {
                arr[i] = Math.random() * 10;
            }
            n--;
        }
    }
    else {
        alert("Wrong number!");
    }
    return arr;
}


function getRound(arr) {        //round(floor) an array.
    var newArr = arr.map(function(n) {
        return Math.floor(n);
    });
    return newArr;
}


function getFixed(arr) {        //fix by 3 chars after dot each element of an array.
    var newArr = arr.map(function(n) {
        return n.toFixed(3);
    });
    return newArr;
}


function getFractional(arr) {   //get the fractional part of each element of an array.
    var newArr = arr.map(function(n) {
        if (~n.toString().indexOf(".")) {
            return n.substring(n.indexOf(".") + 1);
        }
        else {
            alert("A number doesn't have a fractional part.");
        }
    });
    return newArr;
}


//alert(getRound(setArray(7)));
//alert(getFixed(setArray(7)));
//alert(getFractional(getFixed(setArray(7))));