Escape character for single quotes. Is it really required in String?

[Mausam]

Hello,

http://java.sun.com/docs/books/jls/second_edition/html/lexical.doc.html#101089
defines escape character for single character as well.

But single quote works fine in String without any escape character.

public class Class1 {

private static String str = "I have a single quote. That's it";
private static String str1 = "I have a single quote. That\'s it";
public static void main(String[] args) {
System.out.println(str);
System.out.println(str1);
}
}

How the two string is different? And when should I use escape
character for single quote?

 

[Mausam]

Correction :http://java.sun.com/docs/books/jls/second_edition/html/lexical.doc.html#101089
defines escape character for single quote as well.

 

[Mausam]

In character literals.

char apostrophe = '\'';

Thanks. For char it makes sense. But then my understanding that this escape character does not make any difference when used in String is correct.

 

[Knute Johnson]

Thanks. For char it makes sense. But then my understanding that this escape character does not make any difference when used in String is correct.

and the Strings are equal;

public class Class1 {

private static String str = "I have a single quote. That's it";
private static String str1 = "I have a single quote. That\'s it";
public static void main(String[] args) {
System.out.println(str);
System.out.println(str1);
System.out.println(str.equals(str1));
}
}


C:\Documents and Settings\Knute Johnson>java Class1
I have a single quote. That's it
I have a single quote. That's it
true

 

[Lew]

http://java.sun.com/docs/books/jls/second_edition/html/lexical.doc.html#101089

That's the wrong document! Why are you citing ancient information? Get current.
http://java.sun.com/docs/books/jls/third_edition/html/j3TOC.html

defines escape character for single character as well.

But single quote works fine in String without any escape character.

public class Class1 {

private static String str = "I have a single quote. That's it";
private static String str1 = "I have a single quote. That\'s it";
public static void main(String[] args) {
System.out.println(str);
System.out.println(str1);
}
}

How the two string is different?

Why do you claim that they're different?

And when should I use escape character for single quote?

When you need to in order to make the expression mean what you intend.