You can add two textbox values and show the result of addition to into the 3rd textbox by pressing the button using JavaScript and HTML code.
Add two numbers in JavaScript with textbox example
Complete HTML example code, where 2 Input textbox is for number and 3rd for show sum of first 2 textboxes. JavaScript function will call on clicking a button.
<html>
<body>
<div>
First Number : <br>
<input type="text" id="text1">
<br>
Second Number : <br>
<input type="text" id="text2">
<br>
Result : <br>
<input type="text" id="res">
<br>
<input type="button" value="Display Result" onclick="addNumber()">
</div>
<script>
function addNumber(){
var f_num = parseInt(document.getElementById("text1").value);
var s_num = parseInt(document.getElementById("text2").value);
var sum = f_num + s_num;
document.getElementById("res").value = sum;
}
</script>
</body>
</html>Output:
Must Read: Add two textbox values and display the sum in a third textbox automatically – Click Here
Do comment if you have any doubts and suggestion on this topic.
Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.
OS: Windows 10
Code: HTML 5 Version