To add two numbers in JavaScript dynamically use onblur Event to call again addition function. Actually, onblur Event Execute a JavaScript when a user leaves an input field:
How to add two numbers in JavaScript dynamically Example.
HTML example code, Automatic both filed will add value when use leave input field.
<!DOCTYPE html>
<html>
<body>
<input type="text" id="Num1" value="1" onblur="reSum();"/>
<input type="text" id="Num2" value="1" onblur="reSum();"/> <br>
<p>Auto Sum</p>
<input type="text" id="Sum" value=""/>
<script>
function reSum()
{
var num1 = parseInt(document.getElementById("Num1").value);
var num2 = parseInt(document.getElementById("Num2").value);
document.getElementById("Sum").value = num1 + num2;
}
</script>
</body>
</html>
Output:
Do comment if you have any doubts an 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