How to get Array Structure with alert() in JavaScript?

Last Updated : 09 Oct, 2024

To display an array structure using alert() in JavaScript, the array can be converted into a string format Array.toString(). This allows the contents of the array to be shown in a readable format within an alert box.

Below are the approaches to get array structure with alert() in JavaScript:

Table of Content

Using arrayName.toString() method
Using join() method

Approach 1: Using arrayName.toString() method

First, take the values in a variable(let arr).
Pass the array name in the alert().
We can directly use the array name because arrayName is automatically converted to arrayName.toString()

Example 1: This example follows the approach discussed above.

html

<!DOCTYPE HTML>
<html>

<head>
    <title>
        How to get array structure
        with alert() in JavaScript?
    </title>
</head>

<body style="text-align:center;" id="body">
    <h1 style="color:green;">
        GeeksForGeeks
    </h1>

    <p id="GFG_UP" style="font-size: 15px; font-weight: bold;">
    </p>

    <button onclick="gfg_Run()">
        Click here
    </button>

    <script>
        let el_up = document.getElementById("GFG_UP");
        let arr = [1, 2, 4, 6, 9];
        el_up.innerHTML =
"Click on the button to see the array structure using Alert().<br> Array is = "
            + arr;

        function gfg_Run() {
            alert(arr);
        }
    </script>
</body>

</html>

Output:

Approach 2: Using join() method

First take the values in a variable(lets arr).
Pass the array name in the alert() .
We can use.join() method for our simplicity to see the array elements each in a line.

Example: This example follows the approach discussed above.