Javascript Function Not Defined Error (But It Is Defined)

ReferenceError: function not defined

javascript:tryingOnceAgain() is referenced to a function in the global scope but you defined tryingOnceAgain function inside function (response) { scope.

To fix that you have to move your tryingOnceAgain function to global scope.

Or just assign it to window object without changing physical place:

window.tryingOnceAgain = function() {...}

Javascript - Function Not Defined (but it is!) after finishing JQuery function

This JavaScript code:

var totalamt = (double) document.getElementById("sum").innerText;

...is invalid JavaScript code, and so the parsing fails, and the function isn't created.

JavaScript is not C# or Java or (insert language here). It doesn't have casting. Just remove the (double) part. If you want to convert that string to a number, use a unary +, the Number function, parseInt, or parseFloat.

For instance, if you want to convert all of the text to a number, and treat a blank as an invalid input, then:

var str = document.getElementById("sum").innerText;
var totalamt = str ? +str : NaN;
if (isNaN(totalamt)) {
    // ...it wasn't a valid number
}

As I mentioned, you could also use parseInt or parseFloat, but beware that they accept numbers with trailing non-numeric characters (parseFloat("123.4abc") is 123.4, for instance).

JavaScript function not defined in c# code

define your javascript inside the C# code as text

Type type = this.GetType();
String key = "CallMyFunction";
ClientScriptManager cs = Page.ClientScript;

if (!cs.IsClientScriptBlockRegistered(type, key))
{
  StringBuilder script = new StringBuilder();
  script.AppendLine("<script type=\"text/javascript\">");
  script.AppendLine("  function Function_Name() {");
  script.AppendLine("    frmMain.Message.value = 'Hello World';");
  script.AppendLine("  }");
  script.AppendLine("</script>");

  cs.RegisterClientScriptBlock(type, key, script.ToString(), false);
}

or read your javascript from a .js file

<script type="text/javascript">
  function Function_Name() {
    frmMain.Message.value = 'Hello World';
  }
</script>

Type type = this.GetType();
String key = "CallMyFunction";
ClientScriptManager cs = Page.ClientScript;

if (!cs.IsClientScriptBlockRegistered(type, key) && File.Exists(path))
{
  string script = File.ReadAllText(path);

  cs.RegisterClientScriptBlock(type, key, script, false);
}

HTML - Body

<body>
  <form id="frmMain" runat="server">
    <input type="text" id="Message" />
    <input type="button" value="Click!" onclick="Function_Name()" />
  </form>
</body>

If you need a one-liner:

Page.ClientScript.RegisterStartupScript(this.GetType(), "CallMyFunction", "function Function_Name() { frmMain.Message.value='Hello World'; }", true);

Page.ClientScript.RegisterStartupScript(this.GetType(), "CallMyFunction", "<script type=\"text/javascript\">function Function_Name() { frmMain.Message.value='Hello World'; }</script>", false);

EDIT:

Using includes

String includeKey = "MyInclude";
String includeFile = "/myInclude.js";
String scriptKey = "CallMyFunction";
String script = "Function_Name();"; //Function inside your included js file.
Type type = GetType();
ClientScriptManager cs = Page.ClientScript;

//register the js file containing the function
if (!cs.IsClientScriptIncludeRegistered(includeKey))
{
    cs.RegisterClientScriptInclude(includeKey, includeFile);
}

//register the script to call the function 
if (!cs.IsClientScriptBlockRegistered(scriptKey))
{
    cs.RegisterClientScriptBlock(type, scriptKey, script, true);
}

function not defined even though it is

You have just typo mistake:

Replace block of handleSaveAlldokumenterAction with following:

function handleSaveAllDokumenterAction() {
$('.wldk-kurser-save-all-dokumenter').on('click', function (event) {
    event.preventDefault();

    $('.wldk-kurser-dokument .wldk-kurser-save-dokument').trigger('click');
});
}

Javascript function is not defined in script?

Just a small mistake

You need to make another script tag and put the function cd inside

<html>
<body>
    <input type="text" id="input_1"/>
    <button type="button" value="Click" onclick="cd()" id="getDatabaseData">Click!</button>
    <script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js">

    </script>
    <script>
    function cd() {
            var inbtn = {};
            inbtn.input = $('#input_1').val();

            console.log('Started...');

            $.ajax({

                type: 'post',
                url: '<%: Url.Action("Trial") %>',
                data: inbtn,
                success: function er() {
                    console.log("Succes!")
                },
                error: function err() {
                    console.log("Error!")
                }
            })
        } 
    </script>
</body>
</html>

I am assuming this is the result you want , because the cd is now defined

enter image description here

Javascript function causing error not defined

Remove the semicolon from the end of your loops.

for (var elementNum = 0; elementNum < array.length; elementNum++) {
    for (var alphaNum = 0; alphaNum < alphaOrder.length; alphaNum++) {
    }