func:getSafe

getSafe(val, key)

Get an item from a str, list, or grid safely when an index is out of bounds:

• str(num): get a character at index or null if index invalid
• str(range): get safe slice or "" if entire range invalid
• list(num): get item at given index or null is index invalid
• list(range): get list slice with safe index
• grid(num): get row at given index or null if index invalid
• grid(range): Grid.getRange with safe range