I want to add some strings to a textarea
which are file basenames. Everything is fine, but the only problem is that it mixes all the values and there are not any line breaks:
var file_name = file.file_name;
var base = new String(file_name).substring(file_name.lastIndexOf('/') + 1);
if(base.lastIndexOf(".") != -1)
base = base.substring(0, base.lastIndexOf("."));
$('textarea#image_Basename').append(base).split('\n');
These are my file basenames:
5b0cd65710052633dc5dcac406a382c4
212asaddgcvjh622sdsds22113554dfd
5sd5weea55rr6qasfdjkloijhj665s6a
But after storing the data in to the database and retrieving it, the result I get is:
5b0cd65710052633dc5dcac406a382c4212asaddgcvjh622sdsds22113554dfd5sd5weea55rr6qasfdjkloijhj665s6a
To preserve newlines that are coming from a database or whatever, replace the newline characters with the HTML entity for a line feed: 

base = base.replace("\n", '
');
$('#image_Basename').append(base);
If you're trying to append each string with a newline at the end, just concatenate it onto the string:
$('#image_Basename').append(base + '
');
Also, you're using split on the textarea
jQuery element, which doesn't make sense as it is an object
not a string
.