JavaScript (+) sign concatenates instead of giving sum?
The + sign concatenates because you haven’t used parseInt(). The values from the textbox are
string values, therefore you need to use parseInt() to parse the value.
After selecting the value from text box, you need to parse that value. Following is the code −
Example
Live Demo
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initialscale=1.0">
<title>Document</title>
<link rel="stylesheet" href="//code.jquery.com/ui/1.12.1/themes/base/jquery-ui.css">
<script src="https://code.jquery.com/jquery-1.12.4.js"></script>
<script src="https://code.jquery.com/ui/1.12.1/jquery-ui.js"></script>
</head>
<body>
FirstNumber:
<input type="num" class="num1" placeholder=""><br>
SecondNumber:<input type="num" class="num2" placeholder=""><br><br>
<input type="button" onclick="sumOfTwoNumbers()" value="Addition">
<p class="output"></p>
<script>
function sumOfTwoNumbers(){
var num1 = document.querySelector(".num1").value;
var num2 = document.querySelector(".num2").value;
var addition = parseInt(num1)+parseInt(num2);
document.querySelector(".output").innerHTML = "The addition of two
numbers= " + addition;
}
</script>
</body>
</html>To run the above program, save the file name “anyName.html(index.html)” and right click on the
file. Select the option “Open with Live Server” in VS Code editor.
Output
This will produce the following output −
Now, enter the value in both the textboxes and click the “Addition” button to get the sum −
Published on 03-Sep-2020 10:40:23
