Thread: How to find ASCII value of string

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  1. #1
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    How to find ASCII value of string

    I know how to find find ASCII value of given character, but I am not getting how to find ASCII value of given string. For example I want to find ASCII value of string "HELLO",so how to do that.

    Thanks a lot in advance for your replies.

  2. #2
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    You cannot find the ascii value of a complete string
    to get the ascii value of a single character you could just cast it to an int


    Code:
    char * str = "HELLO";
    int i, cnt = strlen(str);
    for ( i = 0; i < cnt; ++I )
        printf("%d,", (int)str[i]);
    Kurt

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    Thanks for the reply

  4. #4
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    Strings do not have ASCII values, individual characters do.

    Converting a character to a int only gives its ASCII value if the implementation (compiler, library, host system) uses the ASCII character set. Not all implementations do.
    Right 98% of the time, and don't care about the other 3%.

    If I seem grumpy or unhelpful in reply to you, or tell you you need to demonstrate more effort before you can expect help, it is likely you deserve it. Suck it up, Buttercup, and read this, this, and this before posting again.

  5. #5
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    Thanks for the reply
    so what to do for getting ASCII value of given string"HELLO",actually I want to do XOR operation on given to strings

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    XOR operations are performed on integral values. Strings are not integral values.
    Right 98% of the time, and don't care about the other 3%.

    If I seem grumpy or unhelpful in reply to you, or tell you you need to demonstrate more effort before you can expect help, it is likely you deserve it. Suck it up, Buttercup, and read this, this, and this before posting again.

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    I want to do Encryption of two Strings, so I need to find their ASCII value first and then do XOR operation on that

  8. #8
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    Quote Originally Posted by shyjuu View Post
    I want to do Encryption of two Strings, so I need to find their ASCII value first and then do XOR operation on that
    Look at the previous posts in this thread. Your problem description is meaningless.

    If your requirement is to XOR the characters in the two strings (say the first "encrypted" character is obtained by XORing the first character from each of the two input strings), then simply XOR individual characters using a loop. But no part of that involves an act described as "getting ASCII value of a string" (there is no such operation) let alone doing an XOR "on that".
    Right 98% of the time, and don't care about the other 3%.

    If I seem grumpy or unhelpful in reply to you, or tell you you need to demonstrate more effort before you can expect help, it is likely you deserve it. Suck it up, Buttercup, and read this, this, and this before posting again.

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    Quote Originally Posted by grumpy View Post
    Look at the previous posts in this thread. Your problem description is meaningless.

    If your requirement is to XOR the characters in the two strings (say the first "encrypted" character is obtained by XORing the first character from each of the two input strings), then simply XOR individual characters using a loop. But no part of that involves an act described as "getting ASCII value of a string" (there is no such operation) let alone doing an XOR "on that".
    so for XOR operation I need the decimal value so I was asking, is there any way to directly perform XOR operation on characters???

  10. #10
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    Quote Originally Posted by shyjuu View Post
    so for XOR operation I need the decimal value so I was asking, is there any way to directly perform XOR operation on characters???
    yes

    Code:
        int i;
        char * str = "HELLO";
        char ch = 'A';
        for ( i = 0;str[i] != 0; ++i )
        {
          char temp = str[i] ^ ch;
          printf("%c:%02x\n",temp ,temp );
        }
    All problems in computer science can be solved by another level of indirection,
    except for the problem of too many layers of indirection.
    – David J. Wheeler

  11. #11
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    output shows that xoring two perfectly printable characters - you with big chance get some non-printable characters.

    So after xoring you will need something like base64 encoding to get some nicely printable garbage string similar to the following

    Code:
    -----BEGIN PGP SIGNATURE-----
    Version: GnuPG v2.0.17 (MingW32)
    
    iQEcBAEBAgAGBQJSGXk9AAoJEAgV1kHhjGOoYssIAMHK0RkcHRwLY4Q1Hpjj6jlH
    Cl5SCDGFq+gN6m76X4PBMAUWesvDyh6kQo97VR2UjmboVa9mAQFcKj+T9jGpwe9E
    PvMKv1tYFgWC+j3+uzcl0qQGpaZ5KpsvcjZgQrltkA/r0NrOm7QIe7EIIAp6Nw7x
    WSv5sXUcmewzUHoijbNigd1YNTGoSgH3aVbgRW2IaBSl2Ym+tG4UQakUbu5LWpa5
    Jhngwwp8AnzvkBwTi2JIiy77kNaD+cDUbo/JH6I1lsSCOfsSrIvzij4WzdWBwLO+
    63PkcZuScwY8ewbF5yfPUKMpAY1BXXUtVkI6L2wIdXa2+CKppW1UBQqQqas3+uU=
    =gld1
    -----END PGP SIGNATURE-----
    All problems in computer science can be solved by another level of indirection,
    except for the problem of too many layers of indirection.
    – David J. Wheeler

  12. #12
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    Note that in order for XOR encryption to be effective the key length should be equal to the length of the clear text.

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