character literals

[swapnil paranjape]

    
class abc 
{
  public static void main (String[] args) {
    String a = "abcd";          // 1
    String b = "'\u0041'";      // 2
    String c = "\u0041";        // 3
    String d = "\uD7AF";        // 4
    System.out.print(a+b+c+d);  // 5
}}

A compile-time error is generated at which line?

character literals ..do i need to mug up these .. what is \u followed by no?i saw soo many questions having \u followed by nos.

please suggest any article which will help me to understand this thing .

[wise owen]

A character literal consists of single-quotes which enclose a single Unicode character or a so-called escape sequence.

For example 'A' is a character literal which represents the uppercase letter A; and '\u0041' is an alternative representation
A for as all sequences of a backslash, followed by an ``u'', and four hex digits (giving 16 bits) are replaced by the corresponding Unicode character. Note that the \u-notation is permitted everywhere in a Java program, not just within character literals. This allows all Unicode characters to be specified within a Java program even if the full Unicode character set is not supported by the current environment.

However, not all Unicode characters can be directly given within a character literal. ''' or '\' are not permitted and likewise neither CR (carriage return) nor LF (line feed) which may be used for line terminators.

[Firas Zuriekat]

There is no compliler errors and the output is:
abcd'A'A?

I don't think it's on the exam because none of SCJP5 objective mention unicode chars.

[marc weber]

Originally posted by Firas Zureikat:
...I don't think it's on the exam because none of SCJP5 objective mention unicode chars.

It's implied through the String and Character classes. You certainly don't need to know Unicode inside out, but you do need to know some basics.