StringBuffer no-arg constructor

[suhaas.mohandos@gmail.com]

How do I assign a value to a stringBuffer object if I am using default constructor?

The following code does not compile:

public class StringBufferDemo {
	public static void main(String args[])
	{
		StringBuffer sb1=new StringBuffer();
		sb1="1234567890";
	}
}

PS: I know we can use the constructor StringBuffer(String str), but what is the use of the no-arg constructor if we can assign values only by using StringBuffer(str)?

[jim829]

I have never needed to do this so I don't know. But I just looked at the API and what I do know is how I could approach it and even test it. Did you read the API and look at the methods? Do you see anything that might provide an answer? If I have to read the API to help answer some of these questions then I expect you and others to make an attempt also.

Regards,
Jim

[gimbal2]

a StringBuffer is not a String, so why are you trying to assign a String to a StringBuffer?

[suhaas.mohandos@gmail.com]

There are four constructors for StringBuffer:

StringBuffer( )
StringBuffer(int size)
StringBuffer(String str)
StringBuffer(CharSequence chars)

If I want to use the first version of the overloaded constructor, how to assign a value? You will be ultimately be using 3rd or 4th version of the constructor to assign the value, so what is the use of no-arg constructor?

[DarrylBurke]

Suhaas, you need to get your terminology straight before continuing to post 'questions' here. The line

StringBuffer sb = new StringBuffer();

declares a variable sb of type StringBuffer and assigns a value to it, a reference to a newly created StringBuffer.

What you are referring to as 'a value' is anybody's guess.

db

[suhaas.mohandos@gmail.com]

Ok, lets use the line:

StringBuffer sb = new StringBuffer();

Now suppose I want to assign "abc" to it. How do I go about it?

[gimbal2]

You're still not reading the API documentation. Do you want to be stuck forever? When are you actually going to LISTEN to the advice you ask for?

[DarrylBurke]

Ok, lets use the line:

StringBuffer sb = new StringBuffer();

Now suppose I want to assign "abc" to it. How do I go about it?

There isn't any way you can assign a String literal to a StringBuffer variable in Java.

Maybe you'd be happier with a language that isn't type safe.

db