SW 2022-05-04

//generic_comparators.js
//for "primitive" data types
function howToSortNumbersAsc(x1, x2){
    x1 = Number(x1)
    x2 = Number(x2)
    if (x1>x2) return 1
    if (x1<x2) return -1
    return 0
}//howToSortNumbersAsc

function howToSortNumbersDesc(x1, x2){
    return -1 * howToSortNumbersAsc(x1,x2)
}//howToSortNumbersDesc

function howToSortStringsAsc(x1, x2){
    x1=x1+""
    x2=x2+""
    if (x1>x2) return 1
    if (x1<x2) return -1
    return 0
}//howToSortStringsAsc

function howToSortStringsDesc(x1, x2){
    return -1 * howToSortStringsAsc(x1, x2)
}//howToSortStringsDesc

*************

<!-- 3.html -->
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>3 - Testing Car Collections</title>
    <script src="generic_comparators.js"></script>
    <script src="Car.js"></script>
</head>
<body>
<script>
var c1 = new Car(
    "Ferrari",
    "F1 641",
    ["Prost", "Mansell"],
    [new Date(1990, 12-1, 31), new Date(1990)]
)

var c2 = new Car(
    "McLaren",
    "F1 MP4",
    ["Senna", "Berger"],
    [new Date(1991, 12-1, 31), new Date(1991)]
)

var c3 = new Car(
    "Ferrari",
    "F1 2022",
    ["Leclerc", "Sainz"],
    [new Date(2022, 12-1, 31), new Date(2022)]
)

var col = [c1, c2, c3]
document.write(col)
</script>
</body>
</html>

//Car.js
class Car{
    constructor(
        pBrand="brand", //e.g. "VW"
        pModel="model", //e.g. "Golf"
        pOwners=[], // ["Maria", "John"]
        pInsurance=[] //["a1", "a2"]
    ){
        this.mBrand = pBrand
        this.mModel = pModel
        this.mOwners = pOwners
        this.mInsurance = pInsurance
    }//constructor

    toString(){
        var strHtml = "<ul>"
        strHtml+=`<li><mark>brand:</mark>${this.mBrand}</li>`
        strHtml+=`<li><mark>model:</mark>${this.mModel}</li>`
        strHtml+=`<li><mark>owners:</mark>${this.mOwners}</li>`
        strHtml+=`<li><mark>insurance:</mark>${this.mInsurance}</li>`
        //strHtml+="<li>"+this.mInsurance+"</li>"
        strHtml+="</ul>"
        return strHtml
    }//toString

    sortOwnersAsc(){
        this.mOwners.sort(howToSortStringsAsc)
    }//sortOwnersAsc

    sortOwnersDesc(){
        this.mOwners.sort(howToSortStringsDesc)
    }//sortOwnersDesc

    sortInsuranceAsc(){
        //this.mInsurance.sort(howToSortStringsAsc)
        this.mInsurance.sort(howToSortDatesAsc)
    }//sortInsuranceAsc

    sortInsuranceDesc(){
        //this.mInsurance.sort(howToSortStringsDesc)
        this.mInsurance.sort(howToSortDatesDesc)
    }//sortInsuranceDesc
}//Car

*********************
<!-- 2.html -->
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Testing Car</title>
    <script src="generic_comparators.js"></script>
    <script src="Car.js"></script>
</head>
<body>
<script>
    var c1 = new Car()
    document.write(c1)

    document.write("<hr>")

    var c2 = new Car(
        "Ferrari",
        "F1 641",
        ["Prost", "Mansell"],
        [new Date(1990, 12-1, 31), new Date(1990, 11-1), 30]
    )
    document.write(c2)

    document.write("<br>After sorting owners, ascending:<br>")
    c2.sortOwnersAsc()
    document.write(c2)

    document.write("<br>After sorting insurance dates, ascending:<br>")
    c2.sortInsuranceAsc()
    document.write(c2)

    document.write("<br>After sorting owners, descending:<br>")
    c2.sortOwnersDesc()
    document.write(c2)

    document.write("<br>After sorting insurance dates, descending:<br>")
    c2.sortInsuranceDesc()
    document.write(c2)
</script>
</body>
</html>