Define function in script and call in input value comes undefined function

July 19, 2023

I called a function within script tag from an input value, but it throws Error — call to undefined function
Here is the function definition

<script>
 function getSelectValue(sel){
    var lang=sel.options[sel.selectedIndex];
   

    return lang;
}
</script>

I called the function here

  <div class="form-group">
              <input type="hidden" id="value" value="{{getSelectValue(this)}}" >

                    <label for="audiolang" class="input-label">Audio Language</label>
                        <select id="audio_lang" name="audio_lang" class="form-control " onchange="getSelectValue(this)">
                        <option selected disabled value="">Select Language</option>
                            <option value="1">English</option>
                            <option value="2">Arabic</option> 
                            <option value="3">Urdu</option>
                            <option value="4">Hindi</option>
                        </select>
                    </div>

Why this error **call to undefined function getSelectValue() ** is coming.

>Solution :

As I understood you have select in your code and you want to get the selected value.

In select

<select id="mySelect" onchange="setHiddenFieldValue(this)">

In input

<input type="hidden" id="hiddenField">

In function

function setHiddenFieldValue(sel) {
    var lang = sel.options[sel.selectedIndex].value;
    console.log(lang);
    document.getElementById("hiddenField").value = lang; // to set the value
}