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Is it right to use global function in javascript?

I have a question about a global script, I am using the following script right now, as these functions are used globally on every page. (before I have the same functions as the function unit converterdefined in 8 places, now I move it to the global script, so I only define it once.)

My question is: is this really the right way or best practice? I really need them to be defined globally and loaded before other scripts call these methods.

I searched, and an article like this suggests using global functions. https://www.w3schools.com/js/js_best_practices.asp

Avoid global variables

Minimize the use of global variables.

This includes all data types, objects, and functions.

Global variables and functions can be overwritten by other scripts.

Use local variables instead and learn how to use closure.

<!DOCTYPE html>
<html>
<head>
    <script type="text/javascript">
        /*-----------------------------------------------------
            global function for Set/Get Cookie
        ------------------------------------------------------*/
        function setCookie(cname,cvalue,exdays) {
            var d = new Date();
            d.setTime(d.getTime() + (exdays*24*60*60*1000));
            var expires = "expires=" + d.toGMTString();
            document.cookie = cname + "=" + cvalue + ";" + expires + ";path=/";
        }

        function getCookie(name) {
            var value = "; " + document.cookie;
            var parts = value.split("; " + name + "=");
            if (parts.length == 2) return parts.pop().split(";").shift();
        }
        /*-----------------------------------------------------
            global function for ...
        ------------------------------------------------------*/
        function getLBS_Global(p, q, u, b, wb) {
        if (b === null || wb === null) {
            alert("Error in unit conversion, please retry");
        }
        var out = {};
        switch (u) {
            case "8": // A bushel
                out.q = (q * b);
                out.p = (p / b);
                break;
            case "10": // lbs
                out.q = q;
                out.p = p;
                break;
            case "11": // cwt
                out.q = (q * 100);
                out.p = (p / 100);
                break;
            case "12": // metric tonne
                out.q = (q * 2204.62262);
                out.p = (p / 2204.62262);
                break;
            case "136": // W bushel
                out.q = (q * wb);
                out.p = (p / wb);
                break;
        }
        return out;
    }
    </script>
</head>
<body>
...
</body>
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2 answers

yes it really is.

if you do not want to pollute the global area (and avoid collisions by name), it is best practice to wrap your functions inside an object and expose the object to a global area

this is an example, but the idea is to relate the base of functions to their behavior

<script type="text/javascript">
  (function(global){

    function setCookie(cname,cvalue,exdays) {
        var d = new Date();
        d.setTime(d.getTime() + (exdays*24*60*60*1000));
        var expires = "expires=" + d.toGMTString();
        document.cookie = cname + "=" + cvalue + ";" + expires + ";path=/";
    }

    function getCookie(name) {
        var value = "; " + document.cookie;
        var parts = value.split("; " + name + "=");
        if (parts.length == 2) return parts.pop().split(";").shift();
    }

    global.bundleObj = {
      setCookie: setCookie,
      getCookie: getCookie
    }

  })(window)
</script>

then in your code

<script>
  window.bundleObj.setItem()
</script>
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Source: https://habr.com/ru/post/1677289/

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