Counting characters in a line leads to error when empty

Hi there, I hope someone can give me a tip:

I'm counting the characters of a particular line in a text layer using this expression:

line_01_count = src.value.split(/\n|\r/); line_01_count[0].length;

line_02_count = src.value.split(/\n|\r/); line_02_count[1].length;

line_03_count = src.value.split(/\n|\r/); line_03_count[2].length;

This works great, but if the text layer referred to has less than three lines, the expression gives me an error. How can I fix this? Is there maybe a way to disregard a part of an expression if the value is empty to get rid of the error?

Would be glad for some help and sorry if this is a rookie question, just starting to get into expressions a bit more.

Cheers
Mathias