The C Declarations * © baa ype Maa TrateDa type] | [er Deed Daw ype Teche ‘inten Erucraon epteet t em Hoang pia J > float > double } long doubte| Figure2.5 Cate typos | C-data type ean be classified as follows: | (i) Basic Data Type: (a) Integer (int), (b) character (char) , (C) floating point (float) , (d) double floating point (double). (ii) Derived Data Type: Derived data types are pointers, functions and arrays. Pointers are in Chapter 9, functions are explained in Chapter 10 and arrays are explained in Gili) User-defined Type: Struct, union and typedef are user-defined data types, which are ij __ explained in Chapter 13. |G) void Data Type: This datatype is explained in Chapter 10, ee meEEE — ming in C a es egors (Gomtinued) ‘ong itogers (0 IEEE: “ Example’ i ye1234567 oe ni234567) eyword, the or Long keywo aoe (b) Integers Signed and Unsi Table 2.7. and unsigned is given in nthe signed integ The difference betw ned and unsigned integers Table27 0 2 bytes in memory Occupies Range: 0 to 65535 Format specifier is 8u gned int is short unsigned in By default w There are also long unsigned int with range 0 to 4294967295 Example: gned long b=567898; ned short int c=223; When a variable is declared as unsigned the negative range of the data type is transferred to positive, i.e. doubles the largest size of the possible value. This is) to declaring unsigned int; the 16 bit is free and m used to store the sign of the number. Brief description on these data types is given in Tabl Table 28 Difference between signed and unsigned char igned Character Unsigned Character Occupies | bytes in memory Range: 0 to 255 Format specifier: $c Oceupies 1 bytes in memory Ri ge: 128 to 127 Format specifier: When printed using Prints ASCIT Cha: puts tel format specifier, When printed using %c format specifier, character prints ASCII character unsigned char =\pr Fl oats and Doubles: Table 2.9 shows the description of floats and douby, floa eThe C Declarations # 43 9 Difference between floating and double floating ik Double Floating “Float ‘Occupies 4 bytes in memory Occupies 8 bytes in memory Range: 3 Ae~38 to 43.4048 Range: 1.7 e308 10 +1.76+308 Format string Format string: 81f Pxample Example: double yi TThere also exist Long double having ranged 3.4e ~ 4932 to L.le + 4932 and occupies 10 bytes in memory. Example long double ki (4) _ Entire data types in C: The entire data types supported by the Cas illustrated above are given in Table 2.10 for the convenience of the reader for understanding. Table 210 Data types and ther control strings Data Type Size (ytes)___Range Format String rae 1 © 12810 127 * 1 010255 se 2 32,768 to 32,767 si or td 2 0 10 65535 su 4 -2147483648 to 2147483647 1d 4 010 4294967295 elu 4 34e-381034e+38 sf or tg 8 17-3080 1.7 €+ 308 ale 10 34esoa2tole+4932 SE wt a 32768 to 32767 aa ~The sine may vary according to the numberof variables used with enum datatype, 2.12 INTEGER AND FLOAT NUMBER REPRESENTATIONS 2.12.1 | Integer Representation Recall that an integer with sign is called a signed integer. The signed integer hes signs positive or negative. The signs are represented in the computer in the binary format as | for ~ (minus) oi for + (plus) or vibelrerin. The sign bits aivopyeetee oy Taupe (EGS) ) ie of storing the signed number, system reserves the leftmost bit for the representation of the sign of the number. For example, positive signed numbel form. In this form, the sign is represented by binary form. +7 is represented as 0 0000111 15 are represented in the form called signed magnitude yy a binary 0 and the remaining magnitude by equivalentSe 44 ¢ Programming in C ‘The signed negative integers can be represented in any one of the following forms: (a) signed—magnitude form (6) signed—t’s complement form (©) signed—2’s complement form In the signed magnitude form, the sign of the number is represented as 1 and the magnitude lent binary form. Example: Tis represented as 1 0000111 In the signed 1's complement form, the sign of the integer is indicated by shown in 1’s complement form as follows, 7 is represented as 1 1111000 1 and the m ment form as follows, ~1 is represented by 1 1111001 2.12.2 | Floating-Point Representation In most of the applications, fractions are often used. The system of the number represen keeps track of the position of binary and decimal point is better than the fixed-point repre “ -point representation. a a fractional part, The real number is a ers are either positive or negative. The re 4.4 or A545 % 10°. This type of Bee soiicon ee a ‘this scientific form, any number can be expressed as cor we can say the number ‘n’ can be expressed as n=mre of the number system and e is the exponent. Mantissa is s the position of the binary or decimal point. For € indicates the plus sign, Most of the computers