Read over Examples.java. It contains the examples from class and a few extras.

$2.$ Run the code and see if it executes as you expect.

$3.$ Fill in the blanks in Examples$2.$java

"Examples.java"

import java.util.function.$*$;

class Examples

$\{$

public static void main$($String$[]$ args$)$

$\{$

$/*$

Predicate: Takes a single arguement and

returns a boolean

$*/$

Predicate startsWithA $=$ s $->$ s$.$startsWith$("$A$")$;

System.out.println$($startsWithA$.$test$("$hello$"))$;

System.out.println$($startsWithA$.$test$("$apple$"))$;

System.out.println$($startsWithA$.$test$("$Apple$"))$;

Predicate isEven$=$n $->$ n $\%2==0$;

System.out.println$($isEven$.$test$(4))$;

System.out.println$($isEven$.$test$(5))$;

Predicate isOdd$=$n$->!$isEven.test$($n$)$;

System.out.println$($isOdd$.$test$(4))$;

System.out.println$($isOdd$.$test$(5))$;

$/*$

Consumer: Represents an operation that accepts

a single input argument and returns no result

$*/$

Consumer printConsumer $=$ s$->$System.out.println$($s$)$;

printConsumer.accept$("$hello$")$;

Consumer printUpper$=$s$->$System.out.println$($s$.$toUpperCase$())$;

printUpper.accept$("$hello$")$;

Consumer increment$=$n$->$System.out.println$($n$+1)$;

increment.accept$(5)$;

$/*$

Function: Represents a function that accepts

one argument and produces a result.

$*/$

Function stringLength $=$ s $->$ s$.$length$()$;

System.out.println$($stringLength$.$apply$("$hello$"))$;

Function increment$2=$n$->$n$+1$;

System.out.println$($increment$2.$apply$(5))$;

int x$=3$;

x$=$increment$2.$apply$($x$)$;

System.out.println$($x$)$;

$/*$

Supplier: Represents a supplier of results

$*/$

Supplier randomValue$=()->$ Math.random$()$;

for$($int i$=0$;i$<5$;i$++)$

System.out.println$($randomValue$.$get$())$;

$\}$

$\}$

"Examples$2.$java"

import java.util.function.$*$;

import java.util.$*$;

class Examples$2$

$\{$

public static void main$($String$[]$ args$)$

$\{$

$/*$

Write a predicate for each of the following

$*/$

$/**$

To check if a list of strings is empty or not.

$*/$

$/**$

what type can you use so all the lines below

work?

Hint: Look at the Java heirarchy.

$*/$

List strs$=$Arrays.asList$("$hello$","$a$",$"ABC"$)$;

$//$System$.$out.println$($p$.$test$($strs$))$;

$//$System$.$out.println$($p$.$test$($new ArrayList$()))$;

$//$System$.$out.println$($p$.$test$($new LinkedList$()))$;

$/**$

Check if a user is an admin or not.

Test by processing the whole queue

$*/$

Queue users$=$new LinkedList$()$;

users.add$($new User$("$mary$",$"jane",$0))$;

users.add$($new User$("$john$",$"doe",$1))$;

users.add$($new User$("$barbara$",$"jean",$1))$;

users.add$($new User$("$max$",$"smith",$0))$;

$/**$

Check if a users last name is at least $5$ characters long

$*/$

$/**$

Check if a users first name starts with ma

$*/$

$/**$

Check if an integer is between $0,100$

$*/$

$/**$

Check if a users first name contains any charaters

that are not letters

Hint: use $\{\}$ for multiple lines on the left hand side

of $->$

$*/$

$/*$

Write a Consumer function for each

$*/$

$/**$

Multiply every integer of a list by $2$

Hint: use $\{\}$ for multiple lines on the left

hand side of the arrow

$*/$

List values$=$Arrays.asList$(2,56,72,56,57,248)$;

System.out.println$($values$)$;

$//$doubleList$.$accept$($values$)$;

System.out.println$($values$)$;

$/**$

Reverse a list of integers

$*/$

$/*$

Write a supplier to generate a random int

in $[0,100]$

$*/$

$/*$

Write a function for each

$*/$

$/**$

compute the square of a number

$*/$

$/**$

create an uppercase version of a string

$*/$

$/**$

gets the role of a user

$*/$

$/**$

generate a queue of users from a list

$*/$

$\}$

$\}$

class User

$\{$

private final String$[]$ roles$=\{"$admin$",$"student","staff","faculty"$\}$;

private String first,last,role;

public User$($String f$,$String l$,$int r$)$

$\{$

first$=$f;

last$=$l;

role$=$roles$[$r$]$;

$\}$

public String toString$()$

$\{$

return first$+""+$last$+""+$role;

$\}$

public String role$()$

$\{$

return role;

$\}$

public String last$()$

$\{$

return last;

$\}$

public String first$()$

$\{$

return first;

$\}$

$\}$