JSFiddle - React, Tailwind, and code Playground

by puuga

HTML

first number
<input id="number1" type="number" value="1">
<br/>second number
<input id="number2" type="number" value="1">
<br/>
<button onclick="doFib()">click</button>
<div id="output">
    <ul id="list1"></ul>
</div>

JavaScript

//var sum = 0;

function doFib() {
    var number1 = 1 * document.getElementById("number1").value;
    var number2 = 1 * document.getElementById("number2").value;
    var list2 = document.getElementById("output").getElementsByTagName("li");
    var sum = 0;
    //console.log(list2);
    //if(list1.length<1)
    if (list2.length === 0) {
        sum = number1 + number2;
    } else if (list2.length === 1) {
        console.log(list2[0]);
        sum = number2 + 1 * list2[0].innerHTML;
    } else if (list2.length > 1) {
        sum = (1 * list2[list2.length - 1].innerHTML) + (1 * list2[list2.length - 2].innerHTML);
    }

    document.getElementById("list1").innerHTML += "<li>" + sum + "</li>";
}