why are data types important?
so that your code knows what kind of information it’s handling
why have data types (3)
- better error detection
- better modularization
- better documentation
categories of data type (3)
- primitive data types
- character string types
- array types
primitive data types (3)
- numeric types
- boolean types
- character type
data types that represent numbers (4)
- integer
- floating-point
- complex
- decimal
on numeric types:
represent mathematical integers; whole numbers
integer
on numeric types:
represent real numbers with decimals
float
on numeric types:
used for double-precision values
double
on numeric types:
represent numbers with real and imaginary parts
complex
on numeric types:
represents exact decimal representation
decimal
boolean has only two values: __ or __
true, false
represents a single character, stored as numeric codes (ASCII, Unicode)
character type
design considerations of character string types (3)
- implementation
- string length
- operations
what kind of character string type implementation is show below:
subj = “CMSC 124”
primitive (built-in) type
what kind of character string type implementation is show below:
char str[8];
strcpy(str, “CMSC 124”);
array of char
on string length:
string length is fixed once declare
static length
on string length:
string length can vary but with a limit
limited dynamic
on string length:
string length may change without any limitations
dynamic length strings
dynamic length strings, despite being flexible, must also consider the __
additional overhead
string operations (5)
- assignment
- concatenation
- substring
- lexical comparison
- patter matching
what string operation is shown below:
“abc” < “bcd” → True
lexical comparison
what string operation is shown below:
Regex r”^[A-Z]{3}\d{3}$”
pattern matching
a homogeneous collection of data in which each element is identified by its position in the collection
array
__ are usually accessed using the array identifier and an index or subscript
array elements
