7/15까지 문제 한번 풀어보기

s+=a;

int a = Integer.MAX_VALUE

int a;

a=(3>2)?10:20; //String s; 문자열로도 가능

배열 기본형

int[]a = new int[10];

a[0]=100;

//배열은 0부터

int[]b = {10,20,30};

System.out.println(b[0]);

int[]apple = new int[8];//배열 사용방법 1

int[]banana = {10,20,30,40,1,2,3,4};//배열 사용방법 2

System.out.println(apple.length);//배열의 크기

System.out.println(banana.length);

for (int i = 0; i < banana.length; i++) {

System.out.println(banana[i]);//배열갯수 셀 필요가없다.

switch 문

switch(a){

case 10:

break;

default:

break;

}

package practice1;

public class practice1 {

public static void main(String[] args) {

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

System.out.println("5"+"*"+i+"="+(5*i));

}

}

}

package practice1;

public class practice1 {

public static void main(String[] args) {

int s = 0;

for (int i = 0; i <= 100; i++) {

s +=i;

}

System.out.println(s);

}

}

package practice1;

import java.util.Random;

public class practice1 {

public static void main(String[] args) {

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

System.out.println(a);

}

}

package practice1;

import java.util.Random;

public class practice1 {

public static void main(String[] args) {

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

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

System.out.println(a);

}

}

}

package practice1;

import java.util.Random;

public class practice1 {

public static void main(String[] args) {

int s=0;

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

int a = (new Random().nextInt(10));

s +=a;

System.out.println(a);

}

System.out.println(s);

}

}

package practice1;

import java.util.Random;

public class practice1 {

public static void main(String[] args) {

int s=0;

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

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

int q = a%10;

int d = a/10;

int p = q+d;

s =+p;

if(d==0)

{

System.out.println("0"+a+" "+s);

}else

System.out.println(a+ " "+s);

}

}

}

package practice1;

import java.util.Random;

public class practice1 {

public static void main(String[] args) {

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

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

}

}

}

(char) 강제형변환 65->A 아스키코드

package practice1;

import java.util.Random;

import java.util.Scanner;

public class practice1 {

public static void main(String[] args) {

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

System.out.println(input);

}

}

package practice1;

import java.util.Random;

import java.util.Scanner;

public class practice1 {

public static void main(String[] args) {

for (int i = 0; i < 127; i++) {

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

}

}

}

package practice1;

import java.util.Random;

import java.util.Scanner;

public class practice1 {

public static void main(String[] args) {

int a=10;

int b = 200;

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

int t;

t=a;//t는 10

a=b;//a는 200

b=t;//t는 10이었으므로 b=10

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

}

}

package practice1;

public class practice1 {

public static void main(String[] args) {

int a=10,b;

int c=10,d;

b = a++;

d=++c;

System.out.println(b+" "+d);

//++은 따로쓰고 한번더 더해주는게 좋다고함

//ex) x=a++; b=x+c;

}

}

package practice1;

public class practice1 {

public static void main(String[] args) {

int a;

a=(3>2)?10:(5>10)?20:30;

System.out.println(a);

/*a=(3>2)?10:20;

System.out.println(a);

int a = 0;

if(3>2) {

a=10;

System.out.println(a);

}else {

a=20;

System.out.println(a);

}//삼항연산//이중 삼항연산

*/ }

}

package practice1;

import java.util.Scanner;

public class practice1 {

public static void main(String[] args) {

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

switch(input) {

case 10:

System.out.println("호랑이");

break;

case 20:

System.out.println("코끼리");

break;

default:

System.out.println("앵무새");

break;

}

}

}