UrlFetchApp.fetch() skip on empty cell

I’ve written a script that gets an image url from a cell in Google Sheets and adds that image to a template in Google Docs. However, when the cell is empty, the script crashes:

var beforePhoto1 = UrlFetchApp.fetch(row[14]).getBlob();

Really new to programming and would appreciate anyones help as to how to prevent the above code from crashing in the event a cell is empty

Answer

Usually there are two options:

1. Check the value before:

if (row[14] != '') {
  var beforePhoto1 = UrlFetchApp.fetch(row[14]).getBlob();
} else {
  console.log('row[14] was empty');
  var beforePhoto1 = 'default_value';
}

// rest code

2. Try to use the value and skip any error with try/catch:

try {
  var beforePhoto1 UrlFetchApp.fetch(row[14]).getBlob();
} catch(e) {
  console.log('row[14] was empty');
  var var beforePhoto1 = 'default_value';
}

// rest code