Siden det var absolutt ikke noe å gjøre idag så valgte jeg å installere Java JDK (Java Development Kit) for å begynne å programmere med Java som språk istedenfor JavaScript. JavaScript er enklere (syntes jeg) men jeg vil heller programmere i Java. Så jeg lastet ned Java JDK og lastet ned Eclipse og begynte å se på noen videoer. Trykk her for link.
Det var noen ting som var litt vanskelig men jeg begynner å skjønne ting mye bedre nå. Dessverre har jeg ikke gjort noe mer så det var ikke så mye å skrive om idag.
Under her så har jeg skrevet hva jeg har lært i løpet av dagen + litt på fritiden.
Jeg har også forklart en del med kommentarer
Eksempel: //Dette er en kommentar
Nederst på bloggen har jeg også laget en egen kalkulator og jeg har ikke peiling på hvorfor jeg skrev alle kommentarene på engelsk, men jeg gjorde det.
Det er også veldig mye informasjon her så under skrev jeg noen stikkord du kan søke etter ved å holde inne Ctrl og trykke på F.
Keywords to search for:
Dog Java + extends
Public classes and Strings
Scanner Java
Methods that return a value
Numbers
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Dog Java + extends
public class Dog extends Animal {
// Create a class
// class subclass extends superclass
// super class is Animal in this case.
// Type "extends" after the "class name".
// example: public class Dog extends Animal {
// Right click and click on "Source" then "Override/Implement Methods"
// Then choose which method(void) you want to implement
@Override
void isItOnEarth() {
// TODO Auto-generated method stub
super.isItOnEarth();
}
String name;
String breed;
Dog(String n, String b){
name = n;
breed = b;
}
void printName(){
System.out.print(name);
}
void printBreed(){
System.out.print(breed);
}
void dig(){
System.out.print("woof ");
}
void bark(){
System.out.print("wah ");
}
}
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Public classes and Strings
public class StartingPoint {
public static void main(String erik[]){
// Here i have created a class called "Example"
// I refer to that by typing in "Example e = new Example();
// So whenever i want to refer to Example i type E
// I put an example on the bottom here, that says "String s = e.name();
// I then tell the compiler that when i refer to s it will mean:
// in Example class, look for the "name" String that i put up there
Example e = new Example();
String s = e.name();
System.out.print(s);
}
}
This is in the Example class:
I here make the String public so the compilers main method is using that.
public class Example {
public String name(){
String n = "Erik ";
return n;
}
}
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Methods that return a value
public class StartingPoint {
public static void main(String erik[]){
// Under this line where it says "e.damage(200, 1);
// means that my curHealth is 200 and the damage is 1
// I set this up in the "CharacterInterface" Interface.
Erik e = new Erik();
e.damage(200, 1);
System.out.println(e.getHit());
}
}
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Erik Class
public class Erik implements CharacterInterface {
@Override
public String getHit() {
// TODO Auto-generated method stub
String erikGotHit ="Come on, hit harder!";
return erikGotHit;
}
@Override
public int damage(int curHealth, int damage) {
// TODO Auto-generated method stub
int newHealth = curHealth - damage;
if (newHealth >0){
return newHealth;
}else{
return 0;
}
}
}
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CharacterInterface Interface
public interface CharacterInterface {
String getHit();
int damage(int curHealth, int damage);
}
#####################################################################################################################
Scanner Java
import java.util.Scanner;
public class StartingPoint {
public static void main(String trav[]){
String nextLin = " ";
int start = 0;
System.out.println("Enter an Integer");
Scanner inputFromUser = new Scanner(System.in);
int finish;
if (inputFromUser.hasNextInt()){
finish = inputFromUser.nextInt();
System.out.println(nextLin);
System.out.println("Enter a String");
}else{
finish = 1;
System.out.println("Play by the rules, Enter a String");
}
System.out.println(nextLin);
System.out.println("Enter a String");
Scanner inputWords = new Scanner(System.in);
String words = inputWords.nextLine();
System.out.println(nextLin);
while (start < finish) {
System.out.print(words);
start += 1;
}
}
}
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Numbers and calculators
int a = 10;
int b = 20;
long c = 1020120310230123;
long d = 129420350384489533098;
float e = 1.50f;
float f = 3.75f;
double g = .35084534;
double h = 50483984.435345;
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Making a calculator
import java.util.Scanner;
public class StartingPoint {
public static void main(String erik[]){
String invalid;
int answer = 1;
System.out.println("What do you want to do? (+ - * /)");
Scanner inputS = new Scanner(System.in);
String s = inputS.nextLine();
System.out.print("Type a number: ");
Scanner inputA = new Scanner(System.in);
int a = inputA.nextInt();
System.out.print("Type a second number: ");
Scanner inputB = new Scanner(System.in);
int b = inputB.nextInt();
Calculate calculator = new Calculate();
switch (s) {
case "add": answer = calculator.add(a, b);
break;
case "sub": answer = calculator.sub(a, b);
break;
case "div": answer = calculator.div(a, b);
break;
case "tim": answer = calculator.add(a, b);
break;
default: invalid = "Invalid input";
}
System.out.println(answer);
}
}
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public interface Equations {
int add(int a, int b);
int sub(int a, int b);
int div(int a, int b);
int tim(int a, int b);
}
--------------------------------------------------------------------------------------------------------------------------
public class Calculate implements Equations {
@Override
public int add(int a, int b) {
// TODO Auto-generated method stub
int answer = a + b;
return answer;
}
@Override
public int sub(int a, int b) {
// TODO Auto-generated method stub
int answer = a- b;
return answer;
}
@Override
public int div(int a, int b) {
// TODO Auto-generated method stub
int answer = a / b;
return answer;
}
@Override
public int tim(int a, int b) {
// TODO Auto-generated method stub
int answer = a * b;
return answer;
}
}
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