How to append semi-colon on to each element in an ArrayList [duplicate]

Answer 1

As a primitive solution you may use:

for (int i = 0; i < emailAddresses.size(); i++) {
    emailAddresses.set(i, emailAddresses.get(i).concat(";"));
}

Answer 2

Removing commas with semi-colons doesn't sounds to me a full proof solution that will grantee to not break in future. Since that requires doing syso on list and then use regex to replace commas and brackets. Instead I'll use StringBuilder, iterate over the list and append semi-colons.

StringBuilder str = new StringBuilder();
for(int i=0; i< emailAddresses.size(); i++ )
{
    str.append(emailAddresses.get(i));
    //to skip last emailAddress 
    if(i+1 == emailAddresses.size())
        continue;
    str.append(";");
}
System.out.println(str.toString());

Answer 3

You can add semicolon to each element while adding them to ArrayList. But suppose you want to do some processing later on, so now you have to take care of that extra semicoln you have added.

So a better solution could be, just add all element as they are and just print below line on the recipient filed where you want them:

System.out.println(emailAddresses .toString().replace("[", "").replace("]", "").replace(",", ";"));

If any problem ask in comment section.

Answer 4

Assuming that you use Java 8, you could do that using the Stream API with joining(CharSequence delimiter) as collector allowing to concatenate the input elements, separated by the specified delimiter, in encounter order as next:

String emails = emailAddresses.stream().collect(Collectors.joining(";"));