The cost of Strings

[Garp]

Hi All,
can somebody make me clear this way? How it is possible to write better ?

pulbic class Log
{
public static void log(String s, String t)
{
System.out.println("heading" + s + "trailer" + t);
}
}



The cost of Strings: The String concatenation operator + looks innocent but involves a lot
of work. The compiler can efficiently concatenate constant strings, but a variable string
requires considerable processing. For example, if s and t are String variables:
System.out.println("heading" + s + "trailer" + t);
this requires a new StringBuffer, appending arguments, and converting the result back to a
String with toString( ). This costs both space and time. If you're appending more than one
String, consider using a StringBuffer directly, especially if you can repeatedly reuse it in a
loop. Preventing the creation of a new StringBuffer on each iteration saves the object
creation time of 980 seen earlier. Using substring( ) and the other String methods is usually
an improvement. When feasible, character arrays are even faster. Also notice that
StringTokenizer is costly because of synchronization.


THX
Garp

 

[daniel135]

How about you showed us how to do it instead of showing us how not to do it? Your arguments seem sound, I just would remember better with an example and you wouldn't have to spend so much time explaining it.

 

[Garp]

Thanks Dan,
but in this (how to do it instead of showing us how not to do it? ) is my problem I know how not to do it but ....my question and modest request sound

how add String together without waste of time.

maybe is possible something like this

pulbic class Log{
MyStringBuffer sb = new MyStringBuffer();

public static void log(String s, String t) {
sb.emptyMySB();
sb.append("heading"
sb.append(s);
sb.append("trailer"
sb.append(t);
System.out.println(sb.toString());
}
}

but i don't think that is "elegant.."
please can someGuru help me
THX
G.

 

[daniel135]

Here's how I might do it:

pulbic class Log
{
public static void log(String s, String t)
{
MyStringBuffer sb = new MyStringBuffer("heading"
sb.append(s).append("trailer&quot.append(t);
System.out.println(sb.toString());
}
}

that looks pretty enough to me. what do you think?

 

[Garp]

Hmm, yes ..but above has been writen

Preventing the creation of a new StringBuffer on each iteration saves the object
creation time of 980 seen earlier


your example unsolved not thing