Slide 1
Slide 1 text
@TTGonda
collectiveidea.com
Kotlin: Uncovered
Victoria Gonda
www.victoriagonda.com
@TTGonda
Slide 2
Slide 2 text
@TTGonda
collectiveidea.com
Holland, MI
Dancer
Collective Idea
Slide 3
Slide 3 text
@TTGonda
collectiveidea.com
I ❤
Programming
Languages
Slide 4
Slide 4 text
@TTGonda
collectiveidea.com
DEFINE('BUBBLE(A,ALEN)I,J,UB,TMP') :
(BUBBLE_END)
BUBBLE I = 1; UB = ALEN
OUTER GT(UB,1) :F(BDONE)
J = 1
INNER LE(A, A) :S(INCRJ)
TMP = A
A = A
A = TMP
INCRJ J = LT(J + 1,UB) J + 1 :S(INNER)
UB = UB - 1 :(OUTER)
BDONE BUBBLE = A :(RETURN)
BUBBLE_END
NUMBERS = '33 99 15 54 1 20 88 47 68 72'
OUTPUT = "Unsorted List"
OUTPUT = NUMBERS;
NUMARRAY = ARRAY(10)
FLOOP I = I + 1
NUMBERS SPAN('0123456789') . NUMARRAY =
:S(FLOOP)
BUBBLE(NUMARRAY,10); NUMBERS = ''
SLOOP J = J + 1;
NUMBERS = NUMBERS NUMARRAY '
' :S(SLOOP)
OUTPUT = TRIM(NUMBERS)
END
SNOBOL
Slide 5
Slide 5 text
@TTGonda
collectiveidea.com
HAI 1.2
CAN HAS STDIO?
VISIBLE "IS KITTAH GAME!"
VISIBLE "ENTER 'HELP' FOR CONTROLS"
VISIBLE ""
I HAS A NAME
VISIBLE "WHAT IS KITTAH'S NAME?"
GIMMEH NAME
I HAS A ACTION
VISIBLE SMOOSH "WAT U WANTING TO DO WITH " NAME "?" MKAY
GIMMEH ACTION
IM IN YR LOOP NERFIN YR PURRS TIL BOTH SAEM ACTION AN "KBYE"
BOTH SAEM ACTION AN "HELP", O RLY?
YA RLY
VISIBLE "PET"
VISIBLE "FEED"
VISIBLE "IS HAPPY?"
VISIBLE "KBYE"
MEBBE BOTH SAEM ACTION AN "PURRS"
VISIBLE SMOOSH "PURRS: " PURRS MKAY
MEBBE BOTH SAEM ACTION AN "FEED"
VISIBLE SMOOSH "YOU DID FEED " NAME ". " NAME " IS HAPPY WITH FOOD." MKAY
PURRS R SUM OF PURRS AN 3
LOLCODE
Slide 6
Slide 6 text
@TTGonda
collectiveidea.com
Slide 7
Slide 7 text
@TTGonda
collectiveidea.com
“Statically typed programming language
for the JVM, Android and the browser”
Slide 8
Slide 8 text
@TTGonda
collectiveidea.com
Statically Typed
Slide 9
Slide 9 text
@TTGonda
collectiveidea.com
Statically Typed
final String name = "Victoria";
val name = "Victoria"
Slide 10
Slide 10 text
@TTGonda
collectiveidea.com
Null Safety
Slide 11
Slide 11 text
@TTGonda
collectiveidea.com
Null Safety
NullPointerException
Slide 12
Slide 12 text
@TTGonda
collectiveidea.com
Concise
Slide 13
Slide 13 text
@TTGonda
collectiveidea.com
map{$P=$P[$f^ord($p{$_})&6];$p{$_}=/ ^$P/ix?$P:close$_}
Perl
Slide 14
Slide 14 text
@TTGonda
collectiveidea.com
Slide 15
Slide 15 text
@TTGonda
collectiveidea.com
Slide 16
Slide 16 text
@TTGonda
collectiveidea.com
Java Virtual Machine
Slide 17
Slide 17 text
@TTGonda
collectiveidea.com
Java Virtual Machine
Slide 18
Slide 18 text
@TTGonda
collectiveidea.com
Java Virtual Machine
*.class
Slide 19
Slide 19 text
@TTGonda
collectiveidea.com
Slide 20
Slide 20 text
@TTGonda
collectiveidea.com
Slide 21
Slide 21 text
@TTGonda
collectiveidea.com
Data Classes
Null Safety
Delegation
Class Extensions
Lambdas
Slide 22
Slide 22 text
@TTGonda
collectiveidea.com
Classes
Slide 23
Slide 23 text
@TTGonda
collectiveidea.com
class User(
val firstName: String,
var lastName: String?
)
Classes
Slide 24
Slide 24 text
@TTGonda
collectiveidea.com
public final class User {
@NotNull
private final String firstName;
@Nullable
private String lastName;
public User(@NotNull String firstName, @Nullable String lastName) {
Intrinsics.checkParameterIsNotNull(firstName, "firstName");
super();
this.firstName = firstName;
this.lastName = lastName;
}
@NotNull
public final String getFirstName() {
return this.firstName;
}
@Nullable
public final String getLastName() {
return this.lastName;
}
public final void setLastName(@Nullable String var1) {
this.lastName = var1;
}
}
Slide 25
Slide 25 text
@TTGonda
collectiveidea.com
public final class User {
Slide 26
Slide 26 text
@TTGonda
collectiveidea.com
@NotNull
private final String firstName;
@Nullable
private String lastName;
public final class User {
Slide 27
Slide 27 text
@TTGonda
collectiveidea.com
public User(@NotNull String firstName, @Nullable String lastName) {
Intrinsics.checkParameterIsNotNull(firstName, "firstName");
super();
this.firstName = firstName;
this.lastName = lastName;
}
public final class User {
@NotNull
private final String firstName;
@Nullable
private final String lastName;
Slide 28
Slide 28 text
@TTGonda
collectiveidea.com
public User(@NotNull String firstName, @Nullable String lastName) {
Intrinsics.checkParameterIsNotNull(firstName, "firstName");
super();
this.firstName = firstName;
this.lastName = lastName;
}
public final class User {
@NotNull
private final String firstName;
@Nullable
private final String lastName;
public static void checkParameterIsNotNull(
Object value, String paramName) {
if (value == null) {
// prints error with stack trace
throwParameterIsNullException(paramName);
}
}
Slide 29
Slide 29 text
@TTGonda
collectiveidea.com
public User(@NotNull String firstName, @Nullable String lastName) {
Intrinsics.checkParameterIsNotNull(firstName, "firstName");
super();
this.firstName = firstName;
this.lastName = lastName;
}
public final class User {
@NotNull
private final String firstName;
@Nullable
private final String lastName;
public static void checkParameterIsNotNull(
Object value, String paramName) {
if (value == null) {
// prints error with stack trace
throwParameterIsNullException(paramName);
}
}
Caused by:
java.lang.IllegalStateException: firstName must not be null
at com.project.User.(User.kt:8)
Slide 30
Slide 30 text
@TTGonda
collectiveidea.com
public User(@NotNull String firstName, @Nullable String lastName) {
Intrinsics.checkParameterIsNotNull(firstName, "firstName");
super();
this.firstName = firstName;
this.lastName = lastName;
}
public final class User {
@NotNull
private final String firstName;
@Nullable
private final String lastName;
Slide 31
Slide 31 text
@TTGonda
collectiveidea.com
@NotNull
public final String getFirstName() {
return this.firstName;
}
@Nullable
public final String getLastName() {
return this.lastName;
}
public final void setLastName(@Nullable String var1) {
this.lastName = var1;
}
}
Intrinsics.checkParameterIsNotNull(lastName, "lastName");
super();
this.firstName = firstName;
this.lastName = lastName;
}
Slide 32
Slide 32 text
@TTGonda
collectiveidea.com
data class User(
val firstName: String,
var lastName: String?
)
Data Classes
Slide 33
Slide 33 text
@TTGonda
collectiveidea.com
public final class User {
@NotNull
private final String firstName;
@Nullable
private String lastName;
public User(@NotNull String firstName, @Nullable String lastName) {
Intrinsics.checkParameterIsNotNull(firstName, "firstName");
super();
this.firstName = firstName;
this.lastName = lastName;
}
@NotNull
public final String getFirstName() {
return this.firstName;
}
@Nullable
public final String getLastName() {
return this.lastName;
}
public final void setLastName(@Nullable String var1) {
this.lastName = var1;
}
@NotNull
public final String component1() {
return this.firstName;
}
@Nullable
public final String component2() {
return this.lastName;
}
@NotNull
public final User copy(@NotNull String firstName, @Nullable String lastName) {
Intrinsics.checkParameterIsNotNull(firstName, "firstName");
return new User(firstName, lastName);
}
// $FF: synthetic method
// $FF: bridge method
@NotNull
public static User copy$default(User var0, String var1, String var2, int var3, Object var4) {
if((var3 & 1) != 0) {
var1 = var0.firstName;
}
if((var3 & 2) != 0) {
var2 = var0.lastName;
}
return var0.copy(var1, var2);
}
public String toString() {
return "User(firstName=" + this.firstName + ", lastName=" + this.lastName + ")";
}
public int hashCode() {
return (this.firstName != null?this.firstName.hashCode():0) * 31 + (this.lastName != null?this.lastName.hashCode():0);
}
public boolean equals(Object var1) {
if(this != var1) {
if(var1 instanceof User) {
User var2 = (User)var1;
if(Intrinsics.areEqual(this.firstName, var2.firstName) && Intrinsics.areEqual(this.lastName, var2.lastName)) {
return true;
}
}
return false;
} else {
return true;
}
}
}
Slide 34
Slide 34 text
@TTGonda
collectiveidea.com
@NotNull
public final String component1() {
return this.firstName;
}
@Nullable
public final String component2() {
return this.lastName;
}
}
public final void setLastName(@Nullable String
this.lastName = var1;
}
Slide 35
Slide 35 text
@TTGonda
collectiveidea.com
@NotNull
public final String component1() {
return this.firstName;
}
@Nullable
public final String component2() {
return this.lastName;
}
}
public final void setLastName(@Nullable String
this.lastName = var1;
}
// Destructuring Data Class Declarations
val user = User("Victoria", "Gonda")
val (firstname, lastname) = user
Slide 36
Slide 36 text
@TTGonda
collectiveidea.com
@NotNull
public final String component1() {
return this.firstName;
}
@Nullable
public final String component2() {
return this.lastName;
}
}
public final void setLastName(@Nullable String
this.lastName = var1;
}
Slide 37
Slide 37 text
@TTGonda
collectiveidea.com
@NotNull
public final User copy(
@NotNull String firstName, @Nullable String lastName) {
Intrinsics
.checkParameterIsNotNull(firstName, "firstName");
return new User(firstName, lastName);
}
return this.firstName;
}
@Nullable
public final String component2() {
return this.lastName;
}
Slide 38
Slide 38 text
@TTGonda
collectiveidea.com
// $FF: synthetic method
// $FF: bridge method
@NotNull
public static User copy$default(
User var0, String var1, String var2, int var3, Object var4) {
if((var3 & 1) != 0) {
var1 = var0.firstName;
}
if((var3 & 2) != 0) {
var2 = var0.lastName;
}
return var0.copy(var1, var2);
}
public final User copy(
@NotNull String firstName, @Nullable String lastName) {
Intrinsics
.checkParameterIsNotNull(firstName, "firstName");
return new User(firstName, lastName);
}
Slide 39
Slide 39 text
@TTGonda
collectiveidea.com
// $FF: synthetic method
// $FF: bridge method
@NotNull
public static User copy$default(
User var0, String var1, String var2, int var3, Object var4) {
if((var3 & 1) != 0) {
var1 = var0.firstName;
}
if((var3 & 2) != 0) {
var2 = var0.lastName;
}
return var0.copy(var1, var2);
}
public final User copy(
@NotNull String firstName, @Nullable String lastName) {
Intrinsics
.checkParameterIsNotNull(firstName, "firstName");
return new User(firstName, lastName);
}
val user1 = user.copy()
val user2 = user.copy(firstName = "Tori")
val user3 = user.copy(lastName = null)
val user4 = user.copy(firstName = "Josh", lastName = "Kovach")
Slide 40
Slide 40 text
@TTGonda
collectiveidea.com
// $FF: synthetic method
// $FF: bridge method
@NotNull
public static User copy$default(
User var0, String var1, String var2, int var3, Object var4) {
if((var3 & 1) != 0) {
var1 = var0.firstName;
}
if((var3 & 2) != 0) {
var2 = var0.lastName;
}
return var0.copy(var1, var2);
}
public final User copy(
@NotNull String firstName, @Nullable String lastName) {
Intrinsics
.checkParameterIsNotNull(firstName, "firstName");
return new User(firstName, lastName);
}
Slide 41
Slide 41 text
@TTGonda
collectiveidea.com
public String toString() {
return "User(firstName=" + this.firstName +
", lastName=" + this.lastName + ")";
}
if((var3 & 1) != 0) {
var1 = var0.firstName;
}
if((var3 & 2) != 0) {
var2 = var0.lastName;
}
return var0.copy(var1, var2);
}
Slide 42
Slide 42 text
@TTGonda
collectiveidea.com
public int hashCode() {
return (this.firstName != null?
this.firstName.hashCode():0) * 31 +
(this.lastName != null?
this.lastName.hashCode():0);
}
public String toString() {
return "User(firstName=" + this.firstName +
", lastName=" + this.lastName + ")";
}
Slide 43
Slide 43 text
@TTGonda
collectiveidea.com
public boolean equals(Object var1) {
if(this != var1) {
if(var1 instanceof User) {
User var2 = (User)var1;
if(Intrinsics.areEqual(this.firstName, var2.firstName) &&
Intrinsics.areEqual(this.lastName, var2.lastName)) {
return true;
}
}
return false;
} else {
return true;
}
}
}
this.firstName.hashCode():0) * 31 +
(this.lastName != null?
this.lastName.hashCode():0);
}
Slide 44
Slide 44 text
@TTGonda
collectiveidea.com
public final class User {
@NotNull
private final String firstName;
@Nullable
private String lastName;
public User(@NotNull String firstName, @Nullable String lastName) {
Intrinsics.checkParameterIsNotNull(firstName, "firstName");
super();
this.firstName = firstName;
this.lastName = lastName;
}
@NotNull
public final String getFirstName() {
return this.firstName;
}
@Nullable
public final String getLastName() {
return this.lastName;
}
public final void setLastName(@Nullable String ) {
this.lastName = ;
}
@NotNull
public final String component1() {
return this.firstName;
}
@Nullable
public final String component2() {
return this.lastName;
}
@NotNull
public final User copy(@NotNull String firstName, @Nullable String lastName) {
Intrinsics.checkParameterIsNotNull(firstName, "firstName");
return new User(firstName, lastName);
}
// $FF: synthetic method
// $FF: bridge method
@NotNull
public static User copy$default(User var0, String var1, String var2, int var3, Object var4) {
if((var3 & 1) != 0) {
var1 = var0.firstName;
}
if((var3 & 2) != 0) {
var2 = var0.lastName;
}
return var0.copy(var1, var2);
}
public String toString() {
return "User(firstName=" + this.firstName + ", lastName=" + this.lastName + ")";
}
public int hashCode() {
return (this.firstName != null?this.firstName.hashCode():0) * 31 + (this.lastName != null?this.lastName.hashCode():0);
}
public boolean equals(Object var1) {
if(this != var1) {
if(var1 instanceof User) {
User var2 = (User)var1;
if(Intrinsics.areEqual(this.firstName, var2.firstName) && Intrinsics.areEqual(this.lastName, var2.lastName)) {
return true;
}
}
return false;
} else {
return true;
}
}
}
Slide 45
Slide 45 text
@TTGonda
collectiveidea.com
data class User(
val firstName: String = "Victoria",
var lastName: String?
)
Default Values
Slide 46
Slide 46 text
@TTGonda
collectiveidea.com
data class User(
val firstName: String = "Victoria",
var lastName: String?
)
Default Values
// $FF: synthetic method
public DataUser(String var1, String var2, int var3,
DefaultConstructorMarker var4) {
if((var3 & 1) != 0) {
var1 = "Victoria";
}
this(var1, var2);
}
Slide 47
Slide 47 text
@TTGonda
collectiveidea.com
data class User(
val firstName: String = "Victoria",
var lastName: String?
)
Default Values
Slide 48
Slide 48 text
@TTGonda
collectiveidea.com
val user = User(
lastName = "Gonda"
)
Named Parameters
Slide 49
Slide 49 text
@TTGonda
collectiveidea.com
Null Safety
Slide 50
Slide 50 text
@TTGonda
collectiveidea.com
// Wont compile
var maybeString: String? = "Hello"
maybeString.length
Slide 51
Slide 51 text
@TTGonda
collectiveidea.com
Safe Call Operator
val maybeString: String? = “Hello"
maybeString?.length
Slide 52
Slide 52 text
@TTGonda
collectiveidea.com
String maybeString = "Hello";
maybeString.length();
? ? ?
Slide 53
Slide 53 text
@TTGonda
collectiveidea.com
Safe Call Operator
val maybeString: String? = getString()
maybeString?.length
Slide 54
Slide 54 text
@TTGonda
collectiveidea.com
String maybeString = this.getString();
if(maybeString != null) {
maybeString.length();
}
Slide 55
Slide 55 text
@TTGonda
collectiveidea.com
val maybeString: String? = getString()
maybeString!!.length
!! Operator
Slide 56
Slide 56 text
@TTGonda
collectiveidea.com
String maybeString = this.getString();
if(maybeString == null) {
Intrinsics.throwNpe();
}
maybeString.length();
Slide 57
Slide 57 text
@TTGonda
collectiveidea.com
val maybeString: String? = getString()
return maybeString?.let {
// it == maybeString
it.length
}
Null Safe Scoping
Slide 58
Slide 58 text
@TTGonda
collectiveidea.com
String maybeString = this.getString();
return maybeString != null ?
Integer.valueOf(maybeString.length()) : null;
Null Safe Scoping
Slide 59
Slide 59 text
@TTGonda
collectiveidea.com
val maybeString: String? = getString()
return maybeString?.length ?: 0
Elvis Operator ?:
Slide 60
Slide 60 text
@TTGonda
collectiveidea.com
String maybeString = this.getString();
return maybeString != null ?
maybeString.length() : 0;
Elvis Operator ?:
Slide 61
Slide 61 text
@TTGonda
collectiveidea.com
Delegation
Slide 62
Slide 62 text
@TTGonda
collectiveidea.com
class CopyPrinter(copier: Copy, printer: Print)
: Copy by copier, Print by printer
interface Copy {
fun copy(page: Page): Page
}
interface Print {
fun print(page: Page)
}
Slide 63
Slide 63 text
@TTGonda
collectiveidea.com
public final class CopyPrinter implements Copy, Print {
// $FF: synthetic field
private final Copy $$delegate_0;
// $FF: synthetic field
private final Print $$delegate_1;
public CopyPrinter(@NotNull Copy copier, @NotNull Print printer) {
Intrinsics.checkParameterIsNotNull(copier, "copier");
Intrinsics.checkParameterIsNotNull(printer, "printer");
super();
this.$$delegate_0 = copier;
this.$$delegate_1 = printer;
}
@NotNull
public Page copy(@NotNull Page page) {
Intrinsics.checkParameterIsNotNull(page, "page");
return this.$$delegate_0.copy(page);
}
public void print(@NotNull Page page) {
Intrinsics.checkParameterIsNotNull(page, "page");
this.$$delegate_1.print(page);
}
}
public interface Copy {
@NotNull
Page copy(@NotNull Page var1);
}
public interface Print {
void print(@NotNull Page var1);
}
Slide 64
Slide 64 text
@TTGonda
collectiveidea.com
public final class CopyPrinter
implements Copy, Print {
Slide 65
Slide 65 text
@TTGonda
collectiveidea.com
// $FF: synthetic field
private final Copy $$delegate_0;
// $FF: synthetic field
private final Print $$delegate_1;
public final class CopyPrinter
implements Copy, Print {
Slide 66
Slide 66 text
@TTGonda
collectiveidea.com
public CopyPrinter(
@NotNull Copy copier,
@NotNull Print printer) {
Intrinsics.checkParameterIsNotNull(copier, "copier");
Intrinsics.checkParameterIsNotNull(printer, "printer");
super();
this.$$delegate_0 = copier;
this.$$delegate_1 = printer;
}
implements Copy, Print {
// $FF: synthetic field
private final Copy $$delegate_0;
// $FF: synthetic field
private final Print $$delegate_1;
Slide 67
Slide 67 text
@TTGonda
collectiveidea.com
@NotNull
public Page copy(@NotNull Page page) {
Intrinsics.checkParameterIsNotNull(page, “page");
return this.$$delegate_0.copy(page);
}
public void print(@NotNull Page page) {
Intrinsics.checkParameterIsNotNull(page, “page");
this.$$delegate_1.print(page);
}
}
Intrinsics.checkParameterIsNotNull(printer, "print
super();
this.$$delegate_0 = copier;
this.$$delegate_1 = printer;
}
Slide 68
Slide 68 text
@TTGonda
collectiveidea.com
public interface Copy {
@NotNull
Page copy(@NotNull Page var1);
}
public interface Print {
void print(@NotNull Page var1);
}
public void print(@NotNull Page page) {
Intrinsics
.checkParameterIsNotNull(page, "page");
this.$$delegate_1.print(page);
}
}
Slide 69
Slide 69 text
@TTGonda
collectiveidea.com
public final class CopyPrinter implements Copy, Print {
// $FF: synthetic field
private final Copy $$delegate_0;
// $FF: synthetic field
private final Print $$delegate_1;
public CopyPrinter(@NotNull Copy copier, @NotNull Print printer) {
Intrinsics.checkParameterIsNotNull(copier, "copier");
Intrinsics.checkParameterIsNotNull(printer, "printer");
super();
this.$$delegate_0 = copier;
this.$$delegate_1 = printer;
}
@NotNull
public Page copy(@NotNull Page page) {
Intrinsics.checkParameterIsNotNull(page, "page");
return this.$$delegate_0.copy(page);
}
public void print(@NotNull Page page) {
Intrinsics.checkParameterIsNotNull(page, "page");
this.$$delegate_1.print(page);
}
}
public interface Copy {
@NotNull
Page copy(@NotNull Page var1);
}
public interface Print {
void print(@NotNull Page var1);
}
Slide 70
Slide 70 text
@TTGonda
collectiveidea.com
Extension Functions
Slide 71
Slide 71 text
@TTGonda
collectiveidea.com
TextUtils.isEmpty("hello");
Extension Functions
Slide 72
Slide 72 text
@TTGonda
collectiveidea.com
// StringExt.kt
fun String?.isEmpty(): Boolean {
return this == null || this.length == 0
}
Slide 73
Slide 73 text
@TTGonda
collectiveidea.com
"".isEmpty() // true
// StringExt.kt
fun String?.isEmpty(): Boolean {
return this == null || this.length
}
Slide 74
Slide 74 text
@TTGonda
collectiveidea.com
public final class StringExtKt {
public static final boolean isEmpty(
@Nullable String $receiver) {
return $receiver == null || $receiver.length() == 0;
}
}
Slide 75
Slide 75 text
@TTGonda
collectiveidea.com
StringExtKt.isEmpty(""); // true
public final class StringExtKt {
public static final boolean isEmpty(
@Nullable String $receiver) {
return $receiver == null || $receiver.l
}
}
Slide 76
Slide 76 text
@TTGonda
collectiveidea.com
Lambdas
Slide 77
Slide 77 text
@TTGonda
collectiveidea.com
fun firstNSquares(n: Int): Array
= Array(n, { i -> i * i })
// firstNSquares(3)
// -> [0, 1, 4]
Slide 78
Slide 78 text
@TTGonda
collectiveidea.com
@NotNull
public static final Integer[] firstNSquares(int n) {
Integer[] result$iv = new Integer[n];
int i$iv = 0;
int var3 = n - 1;
if(i$iv <= var3) {
while(true) {
Integer var9 = Integer.valueOf(i$iv * i$iv);
result$iv[i$iv] = var9;
if(i$iv == var3) {
break;
}
++i$iv;
}
}
return (Integer[])((Object[])result$iv);
}
Slide 79
Slide 79 text
@TTGonda
collectiveidea.com
@NotNull
public static Integer[] firstNSquares(int n) {
Integer[] resultArray = new Integer[n];
int i = 0;
int max = n - 1;
if(i <= max) {
while(true) {
Integer square = i * i;
resultArray[i] = square;
if(i == max) {
break;
}
++i;
}
}
return resultArray;
}
Slide 80
Slide 80 text
@TTGonda
collectiveidea.com
fun firstNSquares(n: Int): Array
= Array(n, { i -> square(i + 1) })
// firstNSquares(3)
// -> [1, 4, 9]
Slide 81
Slide 81 text
@TTGonda
collectiveidea.com
@NotNull
public static Integer[] firstNSquares(int n) {
Integer[] resultArray = new Integer[n];
int i = 0;
int max = n - 1;
if(i <= max) {
while(true) {
Integer square = square(i+1);
resultArray[i] = square;
if(i == max) {
break;
}
++i;
}
}
return resultArray;
}
Slide 82
Slide 82 text
@TTGonda
collectiveidea.com
inline fun beforeAndAfter(
startString: String,
function: (string: String) -> String
) {
print("Before: $startString")
val after = function(startString)
print("After: $after")
}
Slide 83
Slide 83 text
@TTGonda
collectiveidea.com
inline fun beforeAndAfter(
startString: String,
function: (string: String) -> String
) {
print("Before: $startString")
val after = function(startString)
print("After: $after")
}
public inline fun T.let(block: (T) -> R): R
= block(this)
Slide 84
Slide 84 text
@TTGonda
collectiveidea.com
inline fun beforeAndAfter(
startString: String,
function: (string: String) -> String
) {
print("Before: $startString")
val after = function(startString)
print("After: $after")
}
Slide 85
Slide 85 text
@TTGonda
collectiveidea.com
public final void beforeAndAfter(
@NotNull String startString,
@NotNull Function1 function) {
Intrinsics
.checkParameterIsNotNull(startString, "startString");
Intrinsics
.checkParameterIsNotNull(function, "function");
String after = "Before: " + startString;
System.out.print(after);
after = (String)function.invoke(startString);
String var4 = "After: " + after;
System.out.print(var4);
}
Slide 86
Slide 86 text
@TTGonda
collectiveidea.com
public final void beforeAndAfter(
@NotNull String startString,
@NotNull Function1 function) {
Intrinsics
.checkParameterIsNotNull(startString, "startString");
Intrinsics
.checkParameterIsNotNull(function, "function");
String after = "Before: " + startString;
System.out.print(after);
after = (String)function.invoke(startString);
String var4 = "After: " + after;
System.out.print(var4);
}
public interface Function1 : Function {
public operator fun invoke(p1: P1): R
}
Slide 87
Slide 87 text
@TTGonda
collectiveidea.com
public final void beforeAndAfter(
@NotNull String startString,
@NotNull Function1 function) {
Intrinsics
.checkParameterIsNotNull(startString, "startString");
Intrinsics
.checkParameterIsNotNull(function, "function");
String after = "Before: " + startString;
System.out.print(after);
after = (String)function.invoke(startString);
String var4 = "After: " + after;
System.out.print(var4);
}
Slide 88
Slide 88 text
@TTGonda
collectiveidea.com
fun example() {
beforeAndAfter("hello", { string -> string + " world" })
}
// Output
// “Before: hello"
// “After: hello world"
Slide 89
Slide 89 text
@TTGonda
collectiveidea.com
public final void example() {
String startString$iv = "hello";
String after$iv = "Before: " + startString$iv;
System.out.print(after$iv);
String string = (String)startString$iv;
after$iv = (String)(string + " world");
string = "After: " + after$iv;
System.out.print(string);
}
Slide 90
Slide 90 text
@TTGonda
collectiveidea.com
beforeAndAfter("hello", { string -> string + " world" })
beforeAndAfter("hello", { it + " world" })
beforeAndAfter("hello") { it + " world" }
Lambda Parameters
Slide 91
Slide 91 text
@TTGonda
collectiveidea.com
fun beforeAndAfter(
startString: String,
function: (string: String) -> String
) {
print("Before: $startString")
val after = function(startString)
print("After: $after")
}
Slide 92
Slide 92 text
@TTGonda
collectiveidea.com
public final void example() {
this.beforeAndAfter("hello", (Function1)null.INSTANCE);
}
// Output
// “Before: hello”
// “After: hello world”
Slide 93
Slide 93 text
@TTGonda
collectiveidea.com
Slide 94
Slide 94 text
@TTGonda
collectiveidea.com
// Pseudocode for bytecode
final class BytecodeClass
extends Lambda
implements Function1 {
public void invoke(String string) {
StringBuilder sb = new StringBuilder("hello");
sb.append(" world");
returnValue = sb.toString();
}
static Function1 INSTANCE = new BytecodeClass();
}
Slide 95
Slide 95 text
@TTGonda
collectiveidea.com
// Pseudocode for bytecode
final class BytecodeClass
extends Lambda
implements Function1 {
public void invoke(String string) {
StringBuilder sb = new StringBuilder("hello");
sb.append(" world");
returnValue = sb.toString();
}
static Function1 INSTANCE = new BytecodeClass();
}
public final void example() {
this.beforeAndAfter("hello", (Function1)null.INSTANCE);
}
Slide 96
Slide 96 text
@TTGonda
collectiveidea.com
// Pseudocode for bytecode
final class BytecodeClass
extends Lambda
implements Function1 {
public void invoke(String string) {
StringBuilder sb = new StringBuilder("hello");
sb.append(" world");
returnValue = sb.toString();
}
static Function1 INSTANCE = new BytecodeClass();
}
public final void example() {
this.beforeAndAfter("hello", (Function1)null.INSTANCE);
}
// access flags 0x19
public final static ../../../Lambda$example$1; INSTANCE
Slide 97
Slide 97 text
@TTGonda
collectiveidea.com
// Pseudocode for bytecode
final class BytecodeClass
extends Lambda
implements Function1 {
public void invoke(String string) {
StringBuilder sb = new StringBuilder("hello");
sb.append(" world");
returnValue = sb.toString();
}
static Function1 INSTANCE = new BytecodeClass();
}
Slide 98
Slide 98 text
@TTGonda
collectiveidea.com
Companion Objects
Smart Casting
Collection Functions
Control Flow Structures
Operator Overloading
Named Parameters
Slide 99
Slide 99 text
@TTGonda
collectiveidea.com
Menu > Tools > Kotlin > Show Kotlin Bytecode
or
CMD+SHFT+A and search “Show Kotlin Bytecode”
Slide 100
Slide 100 text
@TTGonda
collectiveidea.com
Code > Convert Java File to Kotlin File
or
CMD+SHFT+A and search “Convert Java File to Kotlin File”
Slide 101
Slide 101 text
@TTGonda
collectiveidea.com
DETOUR
JAVA
Slide 102
Slide 102 text
@TTGonda
collectiveidea.com
Thanks!
Victoria Gonda
www.victoriagonda.com
@TTGonda
Slide 103
Slide 103 text
@TTGonda
collectiveidea.com