What does the ^ = operator mean in C #?

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I have a function in C #, where I decrypt a string and need to convert to a function in SQL Server for technicians to be able to work with the decrypted value.

There is a foreach , which I do not understand how it works: 

var calculoChave = 0;
foreach (var c in chave)
{
    calculoChave ^= c;
}

What does this "^=" mean, and what does it do?

By debugging the code, I realized that when the key has a number, it adds up to 48. Equally, if the key is equal to 3, the value of the key calculation will be 51. If the key has more than 2 numbers, the calculation, and I did not find a logical sequence for it.

    
asked by anonymous 27.01.2015 / 13:32

2 answers

9

This is XOR operator . In case it does an auto assignment. 

calculoChave ^= c;

is the same as 

calculoChave = calculoChave ^ c;

T-SQL has the same operator . As far as I know it does not have the shape contracted but now you know how to expand it.

    
27.01.2015 / 13:45
9

Only by completing @Maniero's response, since you are doing foreach on a String , that means you are traversing the character of chave and performing an XOR between the value of the calculoChave and the decimal value of the current character, just after the result is stored in the calculoChave variable itself, for example: 

chave = "ab"
caractere "a"; decimal = 97; binário = 0110 0001
caractere "b"; decimal = 98; binário = 0110 0010
valor 0 (zero);              binário = 0000 0000

It would look like this: 

1ª iteração
0000 0000   (00)  0       calculoChave
0110 0001   (97) 'a'      caractere atual
---------   (XOR)
0110 0001   (97) 'a'      calculoChave = 97

2ª iteração
0110 0001   (97) 'a'      calculoChave
0110 0010   (98) 'b'      caractere atual
---------   (XOR)
0000 0011   (03)          calculoChave = 3

You can check the ASCII table and look at the decimal and binary value of each character, note that there is a difference between the value 0 (zero) and the character "0" (zero).

    
27.01.2015 / 15:05
Develop for various platforms using C # and Xamarin Studio Doubt about the IF