将ComboBox选定的项目链接到预制的2D阵列

Question

I am trying to populate a textbox with data retrieved from an 2 dimensional array i made. I figured out how to populate the textboxs with array data, but im having some trouble doing so based on the selected item from the combo box i made.

This is what i have so far:

HTML:

<select id="Product" name="selectProduct" onchange="choice()">
                <option value="Empty" selected>---------</option>
                <option value="PC_Repair" id="PCR">Hardware Repair</option>
                <option value="Soft_Repair" id="SR">Software Cleanup</option>
                <option value="Home_Support" id="HS">Home Support</option>
              </select>
              <button type="button" onclick="choice()">Enter</button>
              <textarea id="demo"></textarea>

Javascript:

   <script type="text/javascript">
            function runArray(){    
                var arr = 
                [
                    ["one", "two", "three"],
                    ["four", "five", "six"],
                    ["seven", "eight", "ninne"]
                ]  
            }

            var selected = document.getElementById("Product");

            var selected = document.getElementById("Product");
        var selectedValue = selected.options[selected.selectedIndex].value;

        function choice(){ 
            if(selected.value == "PC_Repair"){
                alert("I did it!")       
                document.getElementById("demo").value = arr[0][0];
            }
        }
        </script>
    </body>

I am now getting the alert, but not the array contents. This is my first post, so please forgive any mistakes in format or procedure. Thank you!

Answer 1

arr is declared inside the function runArray so it won't be accessible from outside, you could perhaps update runArray function to return the array, like below:

function runArray() {
    return [
        ["one", "two", "three"],
        ["four", "five", "six"],
        ["seven", "eight", "ninne"]
    ]
};

and then call it and store the value in arr variable, like so:

var arr = runArray();

Below is the updated code:

function runArray(){    
    return [
        ["one", "two", "three"],
        ["four", "five", "six"],
        ["seven", "eight", "ninne"]
    ]
}

var arr = runArray();

var selected = document.getElementById("Product");

var selectedValue = selected.options[selected.selectedIndex].value;

function choice(){ 
    if(selected.value == "PC_Repair"){
        alert("I did it!")       
        document.getElementById("demo").value = arr[0][0];
    }
}