Questions about jq special effects? Why does if else keep repeating?

such as the title, I want to make a when scrolling to the head of the currently selected element is fixed, and then down to the original position, the current display

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="http://apps.bdimg.com/libs/jquery/1.9.1/jquery.js"></script>
    <style>
        html,
        body {
            padding: 0;
        }

        -sharpheader {
            line-height: 70px;
            text-align: center;
            background-color: red;
        }

        -sharpnav {
            height: 30px;
            margin-top: 20px;
            background-color: blue;
        }

        -sharpwrap {
            height: 1200px;
            background-color: -sharpccc;
            padding: 10px;
            padding-right: 20px;
        }

        -sharpwrap .aside {
            float: left;
            width: 100px;
            height: 400px;
            background-color: green;
            float: left;
        }

        -sharpwrap .main {
            background-color: white;
            overflow: hidden;
            height: 100%;
        }

        -sharpfooter {
            height: 30px;
            background-color: black;
            color: green;
        }
    </style>
</head>

<body>
    <div id="header">header</div>
    <div id="nav">nav</div>
    <div id="wrap">
        <div class="aside">aside</div>
        <div class="main">main</div>
    </div>
    <div id="footer">footer</div>
    <script>
        var this1;
        $.fn.stick = function () {
            this1 = this;
            $(window).on("scroll", function () {
                var wintop = $(window).scrollTop();
                if(wintop>=objtop){
                    console.log(1);
                    if(!this1.attr("inx")){
                        this1.hide();
                        cloneself.css({
                            "display": "block",
                             "opacity": "1",
                             "position":"fixed",
                             "top":0,
                             "margin":0
                        })
                    }
                    this1.attr("inx","true");
                    return;
                }else{
                    if(!this1.attr("inx")){
                        return;
                    }else{
                        console.log(2);
                        cloneself.hide();
                        this1.show();
                        this1.removeAttr("inx");
                        return;
                    }
                }
                       
            })
        }
        $("-sharpnav").stick();
        var objtop = $(this1).offset().top;
        var objwidth = $(this1).width();
        var objheight = $(this1).height();
        var cloneself = $(this1).clone();
        cloneself.css({
            "display": "none",
            "opacity": "0",
            "width": objwidth,
            "height": objheight
        })
        cloneself.insertBefore(this1);
    </script>
</body>

</html>

does not the bug, that the if else always executes at the same time be executed only once by the if else? Why does this bug?

appear?

if I changed the code like this, I wouldn"t have this problem. What"s going on?

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="http://apps.bdimg.com/libs/jquery/1.9.1/jquery.js"></script>
    <style>
        html,
        body {
            padding: 0;
        }

        -sharpheader {
            line-height: 70px;
            text-align: center;
            background-color: red;
        }

        -sharpnav {
            height: 30px;
            margin-top: 20px;
            background-color: blue;
        }

        -sharpwrap {
            height: 1200px;
            background-color: -sharpccc;
            padding: 10px;
            padding-right: 20px;
        }

        -sharpwrap .aside {
            float: left;
            width: 100px;
            height: 400px;
            background-color: green;
            float: left;
        }

        -sharpwrap .main {
            background-color: white;
            overflow: hidden;
            height: 100%;
        }

        -sharpfooter {
            height: 30px;
            background-color: black;
            color: green;
        }
    </style>
</head>

<body>
    <div id="header">header</div>
    <div id="nav">nav</div>
    <div id="wrap">
        <div class="aside">aside</div>
        <div class="main">main</div>
    </div>
    <div id="footer">footer</div>
    <script>
        var this1;
        $.fn.stick = function () {
            this1 = this;
            $(window).on("scroll", function () {
                var wintop = $(window).scrollTop();
                if(wintop>=objtop){
                    console.log(1);
                    
                   
                }else{
                    console.log(2);
                }
                       
            })
        }
        $("-sharpnav").stick();
        var objtop = $(this1).offset().top;
        var objwidth = $(this1).width();
        var objheight = $(this1).height();
        var cloneself = $(this1).clone();
        cloneself.css({
            "display": "none",
            "opacity": "0",
            "width": objwidth,
            "height": objheight
        })
        cloneself.insertBefore(this1);
    </script>
</body>

</html>

-it has been solved that when the scrolling distance is less than the top of the current element, I directly remove the style, and then restore the original value, which is fine

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="http://apps.bdimg.com/libs/jquery/1.9.1/jquery.js"></script>
    <style>
        html,
        body {
            padding: 0;
        }

        -sharpheader {
            line-height: 70px;
            text-align: center;
            background-color: red;
        }

        -sharpnav {
            height: 30px;
            margin-top: 20px;
            background-color: blue;
        }

        -sharpwrap {
            height: 1200px;
            background-color: -sharpccc;
            padding: 10px;
            padding-right: 20px;
        }

        -sharpwrap .aside {
            float: left;
            width: 100px;
            height: 400px;
            background-color: green;
            float: left;
        }

        -sharpwrap .main {
            background-color: white;
            overflow: hidden;
            height: 100%;
        }

        -sharpfooter {
            height: 30px;
            background-color: black;
            color: green;
        }
    </style>
</head>

<body>
    <div id="header">header</div>
    <div id="nav">nav</div>
    <div id="wrap">
        <div class="aside">aside</div>
        <div class="main">main</div>
    </div>
    <div id="footer">footer</div>
    <script>
        var this1;
        $.fn.stick = function () {
            this1 = this;
            $(window).on("scroll", function () {
                var wintop = $(window).scrollTop();

                if (wintop >= objtop) {
                    if (!this1.attr("inx")) {
                        this1.hide();
                        cloneself.css({
                            "display": "block",
                            "opacity": "1",
                            "position": "fixed",
                            "width": objwidth,
                            "height": objheight,
                            "top": 0,
                            "margin": 0
                        })
                    }
                    this1.attr("inx", "true");
                    return;
                } else {
                    if (!this1.attr("inx")) {
                        return;
                    } else {
                        cloneself.removeAttr("style")
                        cloneself.css({
                            "display": "none",
                            "opacity": "0",
                        })
                        this1.show();
                        this1.removeAttr("inx");
                        return;
                    }
                }

            })
        }
        $("-sharpnav").stick();
        var objtop = $(this1).offset().top;
        var objleft = $(this1).offset().left;
        var objwidth = $(this1).width();
        var objheight = $(this1).height();
        var cloneself = $(this1).clone();
        cloneself.css({
            "display": "none",
            "opacity": "0",
        })
        cloneself.insertBefore(this1);
    </script>
</body>

</html>