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# Although the same mask can be written 0xffffffff for

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Unformatted text preview: a type, that is, one declared as type char or int, with or without qualiﬁers such as short, long, or unsigned. Here are some example expression evaluations: C Expression ˜0x41 ˜0x00 0x69 & 0x55 0x69 | 0x55 Binary Expression ˜ ¼½¼¼¼¼¼½ ˜ ¼¼¼¼¼¼¼¼ ¼½½¼½¼¼½ & ¼½¼½¼½¼½ ¼½½¼½¼¼½ | ¼½¼½¼½¼½ Binary Result ½¼½½½½½¼ ½½½½½½½½ ¼½¼¼¼¼¼½ ¼½½½½½¼½ C Result 0xBE 0xFF 0x41 0x7D As our examples show, the best way to determine the effect of a bit-level expression is to expand the hexadecimal arguments to their binary representations, perform the operations in binary, and then convert back to hexadecimal. Practice Problem 2.6: To show how the ring properties of ˆ can be useful, consider the following program: 1 2 3 void inplace_swap(int *x, int *y) { *x = *x ˆ *y; /* Step 1 */ 38 4 5 6 CHAPTER 2. REPRESENTING AND MANIPULATING INFORMATION *y = *x ˆ *y; *x = *x ˆ *y; } /* Step 2 */ /* Step 3 */ As the name implies, we...
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## This note was uploaded on 09/02/2010 for the course ELECTRICAL 360 taught by Professor Schultz during the Spring '10 term at BYU.

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