Back when I was a young, budding nerd, I popped off how there are always 8 bits in a byte. A much wiser programmer raised an eyebrow and quizzed me, “Always?”
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\nToday it seems like all computers set a byte’s size equal to 8 bits, but back in the 1970s some computers held 7 bits in a byte, some 8, and some 9 or 10. A “byte” was merely a quantity and the number of bits dwelling within the byte wasn’t set by some international standard. It was set by the system’s hardware design.<\/p>\n
To deal with such inconsistencies, the C language library offers you some assistance. To confirm various sizes and other hardware-specific trivia, you use the The constants defined in the This code examines only a few of the constants defined in the If you’re curious about the printf()<\/em> function formatting, refer to my post from October of 2013<\/a> on the Here is the sample output on my system, which is a Macintosh running an older version of OS X:<\/p>\n Other constants are defined in You may not know, but the C Library knows its limits. Continue reading limits.h<\/code> header file. It beats guessing.<\/p>\nlimits.h<\/code> file are consistent. Their values, however, are unique to each system. On modern computers, a majority of the defined constants have the same values, although it’s good to run a test program just to be sure.<\/p>\n\r\n#include <stdio.h>\r\n#include <limits.h>\r\n\r\nint main()\r\n{\r\n printf(\"%-16s\\t%20s\\n\",\"VARIABLE\",\"VALUE\");\r\n printf(\"%16s\\t%20d\\n\",\"bits in a byte\",CHAR_BIT);\r\n printf(\"%16s\\t%20d\\n\",\"char max\",CHAR_MAX);\r\n printf(\"%16s\\t%20d\\n\",\"char min\",CHAR_MIN);\r\n printf(\"%16s\\t%20d\\n\",\"signed char max\",SCHAR_MAX);\r\n printf(\"%16s\\t%20d\\n\",\"signed char min\",SCHAR_MIN);\r\n printf(\"%16s\\t%20d\\n\",\"unsigned char\",UCHAR_MAX);\r\n printf(\"%16s\\t%20d\\n\",\"short int max\",SHRT_MAX);\r\n printf(\"%16s\\t%20d\\n\",\"short int min\",SHRT_MIN);\r\n printf(\"%16s\\t%20d\\n\",\"int max\",INT_MAX);\r\n printf(\"%16s\\t%20d\\n\",\"int min\",INT_MIN);\r\n printf(\"%16s\\t%20ld\\n\",\"long max\",LONG_MAX);\r\n printf(\"%16s\\t%20ld\\n\",\"long min\",LONG_MIN);\r\n\r\n return(0);\r\n}<\/pre>\nlimits.h<\/code> header. These are primarily the integer constants, with the “bits per byte” value included for good measure.<\/p>\n%s<\/code> text-formatting conversion character.<\/p><\/blockquote>\nVARIABLE \t VALUE\r\n bits in a byte\t 8\r\n char max\t 127\r\n char min\t -128\r\n signed char max\t 127\r\n signed char min\t -128\r\n unsigned char\t 255\r\n short int max\t 32767\r\n short int min\t -32768\r\n int max\t 2147483647\r\n int min\t -2147483648\r\n long max\t 9223372036854775807\r\n long min\t-9223372036854775808<\/code><\/pre>\nlimits.h<\/code> as well, a few of which are vital to know if you don’t want your code to crash. I’ll demonstrate one of them in next week’s Lesson<\/a>. I’ll also show you how to handle the instance where a constant is undefined.<\/p>\n","protected":false},"excerpt":{"rendered":"