StringBuilder#insertCodePoint

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Stefan Ram - 09 May 2006 18:13 GMT

I have a code point »cp«, which I would like to insert
into a StringBuilder-object »sb« at position 0. So:

sb.insertCodePoint( 0, cp );

The problem is that there is no such method, and I
wonder what the most simple / most straigthforward
way is. I can't even seem to find the constructor

new java.lang.String( cp )

to build a string containing only that code point.

Am I really supposed to write:

sb.insert( 0, new java.lang.String( new int[]{ cp }, 0, 1 ));

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Chris Uppal - 09 May 2006 19:09 GMT

> I have a code point »cp«, which I would like to insert
> into a StringBuilder-object »sb« at position 0. So:

I'm assuming that since you mention code points, then you do mean Unicode
rather than 16-bit char values. I'm also assuming that you don't fancy messing
around with UTF-16 encoding yourself.

> sb.insert( 0, new java.lang.String( new int[]{ cp }, 0, 1 ));

You can improve on that a /bit/:

sb.insert(0, new StringBuilder().appendCodePoint(cp));

I leave it to you to choose which you find least unattractive...

-- chris

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Stefan Ram - 09 May 2006 19:44 GMT

>>sb.insert( 0, new java.lang.String( new int[]{ cp }, 0, 1 ));
>sb.insert(0, new StringBuilder().appendCodePoint(cp));

I will use one of those and just believe (in the religious
sense) that the Hotspot JIT-Compiler will transform this to
something as efficient as

sb.insertCodePoint( cp )

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Chris Uppal - 10 May 2006 09:27 GMT

> I will use one of those and just believe (in the religious
> sense)

;-)

> that the Hotspot JIT-Compiler will transform this to
> something as efficient as
>
> sb.insertCodePoint( cp )

Since inserting into a string is an O(n) operation anyway, I doubt it if makes
much difference.

(But you knew that already, of course)

-- chris

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StringBuilder#insertCodePoint

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