JSFiddle - React, Tailwind, and code Playground

by puuga

HTML

<input id="input" type="text" onkeyup="cal()"/>
<div>sum is <span id="output"></span></div>

JavaScript

// calcurator plus
function cal() {
    var input = document.getElementById("input").value;
    var arr = input.split("+");
    var sum = 0;
    for(var i=0; i<arr.length; i++) {
        sum += parseInt(arr[i]);
    }
    document.getElementById("output").innerHTML = sum;
}