lcoolsingh
asked on
References in c#
Hi there,
Im new to c#, and am not understanding 1 aspect of references. Take the following example:
public class CRunMe{
public static void Main(){
string s = "Default val";
CRunMe.ChangeMe(s);
Console.Writeln(s); // Should show the new value, but it doesnt..
}
public static void ChangeMe(string str){
str = "New value assigned";
}
}
Now according to me, a string type is a reference type, so in the above example, afer returnining from changeme, the string variable 's' should be changed 2 reflect the new value, but it doesnt... why is this.. surely a reference type like the above should be changed? In c++, whenever you pass something as a pointer or a reference parameter, if your intention is to modify the passed in parameter, then this will happen. However if i use the ref keyword, then this change takes place..
Thanks
Im new to c#, and am not understanding 1 aspect of references. Take the following example:
public class CRunMe{
public static void Main(){
string s = "Default val";
CRunMe.ChangeMe(s);
Console.Writeln(s); // Should show the new value, but it doesnt..
}
public static void ChangeMe(string str){
str = "New value assigned";
}
}
Now according to me, a string type is a reference type, so in the above example, afer returnining from changeme, the string variable 's' should be changed 2 reflect the new value, but it doesnt... why is this.. surely a reference type like the above should be changed? In c++, whenever you pass something as a pointer or a reference parameter, if your intention is to modify the passed in parameter, then this will happen. However if i use the ref keyword, then this change takes place..
Thanks
By default all primitive datatypes are passed by value and all objects are passed by reference in c#. "string" is identified as a primitive data type. However, all primitive datatypes can be 'boxed' to object types. The corrsponding object type for the datatype string is String. If you pass a String (not a string, mark the difference in case) as an argument it will be passed by reference.
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string is a very special case which behaves like a value type
ASKER
I tried using the uppercase System.String, and passed this into the above function, but unfortunately this did not work either
try the way i suggested
ASKER
I used your way, and i know that by using ref or out, the intended modification takes place.. but as the string type is kind of a reference type, i thought this would happen naturally...
Thanks all
Thanks all