Important ques: setHeader.addHeader

[amarkirt saroay]

if there exists already a header by name and value :
MyHeader: mydata
Now what will be the result of following code on it?

   
response.addHeader("MyHeader","mydata2")
response.setHeader("MyHeader","mydata3")
response.addHeader("MyHeader","mydata")


 

Ans is mydata3,mydata ...Please explain how?

[Tom Kowalski]

First of all, you should write where have you found this question.

Anyway:

// myHeader: mydata
response.addHeader("MyHeader","mydata2")  // myHeader: mydata, mydata2
response.setHeader("MyHeader","mydata3")  // myHeader: mydata3
response.addHeader("MyHeader","mydata")  // myHeader: mydata3, mydata

when you are using setHeader you are deleting the old contents of the header, and you are puting into it a new value.
when you are using addHeader you are NOT deleting old contents, you just add a new value to this header.

[amarkirt saroay]

Thanks,i took this question from HFJS mock exam.

[Nicky McGrath]

So the real question is:
If you have a Header with multiple values (as occurs after multiple calls to addHeader),
does setHeader replace ALL the existing values.

Good question.

[Omer Haderi]

the spec is clear about setHeader "the values are cleared and replaced with the new value"

therefore all values will be cleared