<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Update Value in Text Field</title>
</head>
<body onload="main()">
<form>
Enter Value
<input type="text" id="myTextField" value="4"><br><br>
<input type="button" id="ComputeValueButton" value="Compute Sqrt">
(press button multiple times and look at textfield)<br><br>
<input type="reset" value="Reset">
</form>
<script>
function main() {
document.getElementById("ComputeValueButton").onclick = displayValue; // DO NOT PUT ()
}
function displayValue() {
let myTextFieldElement = document.getElementById("myTextField");
let textProvided = myTextFieldElement.value;
let numericValue = Number(textProvided);
/* Updating the textfield */
myTextFieldElement.value = Math.sqrt(numericValue);
}
</script>
</body>
</html>