7/10 배움

4번예시

package PACK01;

import java.util.Random;

public class HELLO {

public static void main(String[] args) {

for (int i = 0; i < 10; i++) {

int rn = (new Random().nextInt(100));

int q = rn/10;//몫을 구한다

int r = rn%10;//나머지를 구한다.

int a = q+r;

System.out.println(rn+" "+q+" + "+r+" = "+a);

}

}

}

5번답 

package PACK01;

public class HELLO {

public static void main(String[] args) {

byte a = 10;

short b = 20;

char c = 'T';

int d = 30;

long e = 40;

float g = 3.14f;//실수 4

double h = 3.14;//float보다 크다 8 double은 f안붙여도됨 

boolean k = true;//값은 true,false만 사용가능

}

}

nextInt(n) =n-1까지의 숫자 나타낼수있음 

char ch = 65;

char ch = 'A';

아스키 코드

System.out.println((int)ch);//강제형변환

System.out.println((char)('A'+i));

System.out.println((char)(num));

int A = 65;//'A'나 65나 ch나 같게 나온다

System.out.println((char)A);

package PACK01;

public class HELLO {

public static void main(String[] args) {

int A = 65;

char ch = 'A';

for (int i = 0; i < 26; i++) {

System.out.println((char)(65+i));

//System.out.println((char)A+i);

//System.out.println((char)ch+i);

}

}

}

7번 예시

package PACK01;

import java.util.Random;

import java.util.Scanner;

public class HELLO {

public static void main(String[] args) {

System.out.println("호랑이");

int input = (new Scanner(System.in).nextInt());

System.out.println("코끼리"+input);

}

}

package PACK01;

import java.util.Random;

import java.util.Scanner;

public class HELLO {

public static void main(String[] args) {

int input = (new Scanner(System.in).nextInt());

System.out.println(input);

}

}

package PACK01;

import java.util.Random;

import java.util.Scanner;

public class HELLO {

public static void main(String[] args) {

System.out.println("숫자를 입력하세요");

int input = (new Scanner(System.in).nextInt());

for (int i = 0; i < 10; i++) {

System.out.println(input+"*"+i+"="+(input*i));

}

}

}

8번

System.out.println("아스키코드를 입력하세요 0~127");

int input = (new Scanner(System.in).nextInt());

System.out.println((char)input);

shift enter 상관없이 ㄴ

9번

package PACK01;

public class HELLO {

public static void main(String[] args) {

int a = 30,b = 50, t;

t = a;//t=30 a=30 b=50

System.out.println(a+" "+b+" "+t);

a = b;//a=50 b=50 t=30

b = t;//b=30 a=50 t=30

System.out.println(a+" "+b+" "+t);

}

}

abc

한칸씩 미뤄넣기 

package PACK01;

public class HELLO {

public static void main(String[] args) {

int a = 30,b = 50, c= 15, t ;

System.out.println(a+" "+b+" "+c);

t=a;

a=b;

b=c;

c=t;

System.out.println(a+" "+b+" "+c);

}

}