Why is RunThis(char arg[]) expecting a String?

[Mannie J Chaihan]

I want my function to accept "this is array of chars".

Main()
{
      RunThis("this is an arry of char and not a java.lang.String")
}
 
RunThis(char arg[])
      {
      String var1 = new String(arg);
      .. do stuff with string

Of course I can't. compiler is telling me I need to send a String
What am I doing wrong?

[Jeff Bosch]

Hi, Mannie -

A String is a different thing in Java than it is in C. In C, a null terminated character array is a string; in Java, String is a full-fledged object. So, you can create a char array from the String object that you create when you put text between quotes, or you can change the method parameter to take a String object.

Hope that helps...

[Layne Lund]

Originally posted by Mannie J Chaihan:
I want my function to accept "this is array of chars".

Main()
{
      RunThis("this is an arry of char and not a java.lang.String")
}
 
RunThis(char arg[])
      {
      String var1 = new String(arg);
      .. do stuff with string

Of course I can't. compiler is telling me I need to send a String
What am I doing wrong?

Actually "this IS a String, NOT an array of chars". As described above, a literal value enclosed in double-quotes behaves VERY differently in Java than it does in C/C++. They are actually String objects, not char arrays.

Layne

[Mannie J Chaihan]

Thank you.
A java.lang.String != Char[]
Ok, so how do I write my function so that it will accept the call:

RunThis("this is an arry of char and not a java.lang.String");  

[Mannie J Chaihan]

Well, I tried my only option:

 
RunThis(String var1) { ...}
.
.
RunThis("This is not a string but an array of char, " +
"but java does some crazy boxing un boxing thing and " + 
"has automatically changed my char into a Object even " +
"thou I never used the word new anywhere. At the maximum " +
"I feel a native data type could have been created. " +
"But now, java is going to create an object for this very " +
"long group of charters.")

And Voila.. It still feels very unnatural.
Thank you for your help!
[JAM Edited for formatting of code....]
[ May 11, 2005: Message edited by: Joel McNary ]

[Joel McNary]

That's correct: Java recognizes the "this is a string" as a literal object. This means that you can do things like:

String myString = "this is a string";
int length = "this is a string".length();
boolean areEquals = "this is a string".equals(myString);
boolean isEmpty = "".equals(myString);

There's no need for a primitive type, as the object type is much more flexible. Also, Literal strings are treated internally a little bit differently; only 1 copy of a string is created, so:

boolean areEquals = "this is a string" == myString;

is true, where

boolean areEquals = new String("this is a string") == myString;

is false.