<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Scope & parameter</title>
</head>
<body>
<div id="output"></div><br>
<button onclick="setNum(16)">Set Number to 16</button>
<button onclick="setNum(47)">Set Number to 47</button>
<button onclick="increaseNum()">Increase number by 1</button>
<br><br>
<script>
var outputDiv = document.getElementById('output');
var numToShow = 0;
function setNum(selectedNum){
numToShow = selectedNum;
outputDiv.innerHTML = numToShow;
}
function increaseNum(){
numToShow++;
outputDiv.innerHTML = numToShow;
}
</script>
</body>
</html>