Lesson 11.1: Data Type 1

Data type

defines a collection of data values and a set of predefined operations on those values

Data type

used to easily represent information related to real-world problems

Better error detection

why do we have data types? (1)

Better documentation

why do we have data types? (2)

Primitive Data Types

data types that are not defined in terms of other types

Numeric Types

data types that represent numbers

Integer

represent mathematical integers

2^ (n-1) -1

base of integers, signed or unsigned

Integer

can be implemented using signed-magnitude notation, one’s complement and two’s complement

Floating Point

models real numbers, but most representations are only approximations

Float

standard size; used for single-precision values

Double

twice as long as float types; used for double-precision values

Complex

used to represent complex numbers

Decimal

stores a fixed number of decimal digits, with the decimal point at a fixed position in the value

BCD

each decimal digit is represented by a fixed number of bits

Binary Coded Decimal

meaning of BCD

Boolean Types

value is either true or false

Boolean Types

usually used as flags; makes code more readable

Smallest Efficiently

they are stored in the _ _ accessible cell of memory

Character Type

represents a single character; they are stored in computers as numeric encodings

Character String Types

aka strings; data types whose values consist of sequence of characters

Implementation

implementing strings as a primitive type increases the writability of a language

String length

should _ _ be static or dynamic?

Static Length

string length is fixed once created

Limited Dynamic Length Strings

string length may be within a certain limit assigned during declaration

Dynamic Length Strings

string length may change without any limitations

Additional overhead

dynamic length strings, despite being flexible the _ _ must also be considered

String Assignment

most common operations on strings (1)

String concatenation

most common operations on strings (2)

Substring Reference

returns a reference to the first occurrence of the substring being searched

Lexical Comparison

checks if a string is lexically greater than or less than or equal to another string

Pattern Matching

checks if a string follows a given pattern

Address of the first Char

tells where the string is in the memory

Address of the first char

static length and limited dynamic length strings are bound to storage only once

Complex Memory Management

Address of the first char, dynamic length strings requires _ _ _

Linked list, Adjacent Memory Cells

Address of the first char, dynamic length can be implemented using _ _ or _ _ _

String Type

specifies the type of the string

Fixed

string length, for static strings ->its _ length

Current

string length, for dynamic strings ->its _ length

Current, Max

string length, for limited dynamic strings ->its _ length and _ length