1 / 5

Department of Computer and Information Science, School of Science, IUPUI

Department of Computer and Information Science, School of Science, IUPUI. A First C Program (mixing datatypes). Data Type Conversion. Rule #1 char, short  int float  double Rule #2 (double ← long ← unsigned ← int)

pbevill
Download Presentation

Department of Computer and Information Science, School of Science, IUPUI

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Department of Computer and Information Science,School of Science, IUPUI A First C Program (mixing datatypes)

  2. Data Type Conversion • Rule #1 char, short int float  double • Rule #2(double ← long ← unsigned ← int) • If either operand is double, the other is converted to double, and the result is double • Otherwise, if either operand islong, the other is converted tolong, and the result is long • Otherwise, if either operand is unsigned, the other is converted to unsigned, and the result is unsigned • Otherwise, the operand must beint

  3. Examples Example: c: char, u: unsigned, i: int, d: double, f:float, s: short, l: long, Expression Final Data Type Explanation c – s / i intshortint, int/int, charint, int-int u * 3 – i unsignedint(3)unsigned, unsigned*unsigned=unsigned, intunsigned, unsigned-unsigned=unsigned u * 3.0 – i double unsigneddouble, double*double, intdouble, double-double=double c + i int charint c + 1.0 double charint (rule 1), intdouble(rule 2) 3 * s * l long shortint, int*int, intlong, long*long

  4. Data Type Conversion (cont.) • Note: • Conversion of int to long preserves sign, so does short • Var = expr f = d;/* round off */ i = f; /* truncates fractions part, if the number is too big to fit, the result is undetermined */ i = l; s = i; and c = i; /* may eliminate high order bits */

  5. If a specific type is required, the following syntax may be used, called cast operator. (type) expr Example: float f=2.5; x = (int)f + 1; /* the result is 3, Q:will f value be changed? */ • Unsigned int to int: there is not actual conversion between int and unsigned int. Example:(Assuming 2’s complement machine and int is 2 bytes long) unsigned i = 65535; int j; j = i;/* j will be –1 */ j = -2; unsigned i = 1 + j;/* i= 65535 */

More Related