2 - java data structures

data structure

considered a fundamental building block of all programs

API (Application Programming Interface)

provides built in support for these structures

linked list

hash map

stack

queue

set

types of data structures

linked list

basic structure where each node is linked to others

hash map (table/dictionary)

one of the most versatile structures, uses key value pairs to store data

stack: last in, first out

last item you put in is the first one out, eq. undo button

queue: first in, first out

works like a line at a grocery store, first person first served

set: no duplicates allowed

special structure that does not allow duplicates, if u add the same item twice it will ignore the second one

LocalDate

represents only a date (year, month, day)

LocalTime

represents only time (hour, min, second, nanosecond)

LocalDateTime

represents both date and time together

RegEx

is an API used to define patterns for searching or manipulating strings, commonly used for security

Pattern

Matcher

PatternSyntaxException

key classes in java.util.regex

pattern

defines the pattern used in a search

matcher

used to research for the defined pattern

PatternSyntaxEception

indicates a syntax error in the regex pattern

a-z

0-9

^

.

basic regex symbols

^

define the start of the string for pattern matching

.

represents any single character in the pattern