how to check for empty strings

[praveen kumar gowda]

String name1="praveen";

String name2=new String(praveen);
if(name1=="")
{
}
if(name2=="")
{
}
my doubt is if i create string using new operator can we check against empty as shown in first if statment ..

[William P O'Sullivan]

mostly No. Use compareTo() or equals()

WP

[Jeff Verdegan]

Always use equals() to compare objects' states, not ==. This includes comparing Strings' contents.

Note, however, that String has an isEmpty() method.

[Randall Twede]

i agree sometimes == will work but you should use the String method equals()

[Randall Twede]

isEmpty() certainly is better than equals("") thanks for that tip

[Jeff Verdegan]

William P O'Sullivan wrote:mostly No.

No "mostly" about it. It won't work.

Use compareTo() or equals

No, not compareTo(). It would be better to use equals() than compareTo(), and better to use length() == 0 than equals(), and best of all to use isEmpty().

[William P O'Sullivan]

Try this ... It does work! ;)

	public static void main(String[] args) {

		String empty = "";
		
		if (empty=="") {
			System.out.println("ARE The same");
		} else {
			System.out.println("NOT The same");
		}

Now, For the record I am very against using the "==" for Strings, and recommend NOT using it at all!

WP

[Koen Aerts]

It works because "" goes into the string pool and so you're comparing the same "pointers" (i.e. same objects) with the ==. With that logic, the following would work, too:

String name1="";
String name2=(new String("")).intern();
if (name1 == name2) {
}

[Jeff Verdegan]

William P O'Sullivan wrote:Try this ... It does work! ;)

The OP asked about

if i create string using new operator

. In that context (which I thought is what you were answering), it doesn't work at all.

And even in the context you posted, I wouldn't call it "working." The OP wants to compare the contents of 2 Strings. The code you posted doesn't do that. It happens to produce the same result for that particular case, but I don't call taht "working".