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Because Java is too much of a pain in the ass to have included one in the standard library, here's a simple string join function:

public static String join(String[] pieces){

    return join(pieces, " ");

}

public static String join(String[] pieces, char sep){

    return join(pieces, String.valueOf(sep));

}

public static String join(String[] pieces, String sep){

    if(pieces.length == 0) return "";



    StringBuffer buf = new StringBuffer();

    buf.append(pieces[0]);

    for(int i=1,n=pieces.length; i<n; i++)

        buf.append(sep).append(pieces[i]);

    return buf.toString();

}

Update: Of course, there's also a join function in org.apache.commons.lang.StringUtils.

Permalink | 4 Comments | Tags: Programming | id 7213

17:26 (utc-5)
edited: 2005-08-18 13:51 (utc-5)

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Comments

208.28.3.125 wrote:

The code will break if the first value of the array is null.
~Ajay

∴ 208.28.3.125 | 19-Nov-2008 6:19pm est | #10952

Keith (http://keithdevens.com/) wrote:

The code will break if the first value of the array is null.

Have you run it? It should just append the string "null". And why only if the first value is null? The code calls StringBuffer.append for all elements, not just the first.

∴ Keith | 19-Nov-2008 6:35pm est | http://keithdevens.com/ | #10953

208.28.3.125 wrote:

Hi Keith,
My expected behaviour of the method, which I feel is reasonable - when you encounter a null return empty string.

I saw your comment on http://piehead.livejournal.com/268351.html . Your suggestion was to avoid the flag for the first entry.

if we were to modify your method to behave similar to one I just mentioned, using a flag is easiest way to do it. Please let me know what you think about that?

~Ajay

∴ 208.28.3.125 | 19-Nov-2008 7:02pm est | #10954

Keith (http://keithdevens.com/) wrote:

Meh, don't have null strings in your string arrays imo, but you're welcome to modify the above function to do what you'd like.

∴ Keith | 19-Nov-2008 7:51pm est | http://keithdevens.com/ | #10955

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Wednesday, August 17, 2005

Java join function

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