Edit in JSFiddle

{
  let text = 'defined'; 
  document.getElementById('out1').textContent =  'inside of the block text is ' + text;
}

try {
	document.getElementById('out2').textContent = 'outside of the block text is ' + text;
} catch(e) {
	document.getElementById('out2').textContent = 'outside of the block text is not defined';
}

<div id="out1"></div>
<div id="out2"></div>