javascript - for ループの最後の項目にプロパティを追加する

Question

for (i = 0; i < len; i++) {
    dStep = links[i].getAttribute("data-step"),
    dIntro = links[i].getAttribute("data-intro"),
    linkObj = {
        element: "#step" + dStep,
        intro: dIntro,
        position: "right"
    };
    obj.steps.push(linkObj);

position: "left" をループの最後の項目にのみ追加するにはどうすればよいでしょうか?

Answer 1

if (i == len-1) {
   linkObj.position = "left";
}

Answer 2

// You should almost certainly be using the var keyword
for (var i = 0; i < len; i++) {
    var dStep = links[i].getAttribute("data-step"),
        dIntro = links[i].getAttribute("data-intro"),
        linkObj = {
            element: "#step" + dStep,
            intro: dIntro,
            position: "right"
        };
    obj.steps.push(linkObj);
}
// Take advantage of the fact that JavaScript doesn't have block scoping
linkObj.position = "left";

Answer 3

forこれは配列にプッシュした最後の項目であるため、ループ後に配列の最後の項目のプロパティを追加/変更することもできます。

for (i = 0; i < len; i++) {
    dStep = links[i].getAttribute("data-step"),
    dIntro = links[i].getAttribute("data-intro"),
    linkObj = {
        element: "#step" + dStep,
        intro: dIntro,
        position: "right"
    };
    obj.steps.push(linkObj);
}

// add this line of code after the for loop
obj.steps[obj.steps.length - 1].position = "left";

Answer 4

for (i = 0; i < len; i++) {
    dStep = links[i].getAttribute("data-step"),
    dIntro = links[i].getAttribute("data-intro"),
    linkObj = {
        element: "#step" + dStep,
        intro: dIntro,
        position: "right"
    };

    // try this
    if (i === len - 1) {
        linkObj.position = 'left';
    }

    obj.steps.push(linkObj);