フィボナッチ数

by Canadian Dev Canadian Dev

HTML

<div class="fibonacci-input">
  <input id="input" min="0" type="number" name="fibonacci" placeholder="ここに数字を入力してENTER" />
</div>
<div class="fibonacci-output">
  <span id="output">
    フィボナッチ数
  </span>
</div>

CSS

.fibonacci-input {
  height: 100px;
  width: 100%;
  border: 1px solid black;
}

.fibonacci-input > input {
  width: 100%;
  height: 100%;
  font-size: 1.5em;
  text-align: center;
}
.fibonacci-output {
  height: 100px;
  width: 100%;
  background: black;
  color: white;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 1.5em;
}

JavaScript

var input = document.getElementById('input');
var output = document.getElementById('output');

input.addEventListener('keypress', addActivity)

function addActivity(e) {
	if (e.which === 13) {
  	output.innerHTML = fibonacci(e.target.value);
  }
}

//フィボナッチ数
var fibonacci = function(n) {
	var fibArray = [0, 1];
  for (var i = 0; i < n; i++) {
  	fibArray.push(fibArray[fibArray.length-1] + fibArray[fibArray.length-2])
  }
  return fibArray[n];
}