7/16 복습

package practice1;

public class practice1 {

public static void main(String[] args) {

//우박수

int a=35;

while(true) {

System.out.println(a);

if(a==1) {

System.out.println("우박수");

break;

}

if(a%2==0) {

a=a/2;

}else {

a=a*3+1;

}

}

}

}

package practice1;

public class practice1 {

public static void main(String[] args) {

//삼항연산으로 바꾸기

/*int a=0;

if(2>3) {

a=10;

}else {

a=20;

}

System.out.println(a);*/

int a =(2>3)? 10:20; 

System.out.println(a);

}

}

package practice1;

import java.util.Random;

import java.util.Scanner;

public class practice1 {

public static void main(String[] args) {

//배열형식

int ar[] = new int[10];//int int

int br[] = {1,2,3};//int a[];

//랜덤

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

//입력

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

}

}

///////////////오류

package practice1;

import java.util.Random;

import java.util.Scanner;

class Practice{

void func01() {

System.out.println("함수 1번이 콜되었습니다.");

}

//int타입의 변수 7개를 배열로 선언하세요

//0~10까지의 숫자들을 7개의 배열에 채워넣으시

//배열안의 모든 내용을 출력하세요

void func05() {

int ar[] = new int[7];

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

ar[i] = new Random().nextInt(10);

}

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

System.out.print(ar[i]+" ");

}

int s=0;

System.out.println();

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

s +=ar[i];

}

System.out.println(s);

}

}

public class practice1 {

public static void main(String[] args) {

Practice t1 = new Practice();//cn cn

t1.func01();

t1.func05();

}

}

//이 예외처리는 배열에소 보통 잘못된것 배열의길이는 크거나 같다가 성립될수없음

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 7

at practice1.Practice.func05(practice1.java:14)

at practice1.practice1.main(practice1.java:32)

try catch

package practice1;

import java.util.Random;

import java.util.Scanner;

class Practice{

void func01() {

System.out.println("함수 1번이 콜되었습니다.");

}

void func06(int num) {

System.out.println(num);

return;

}

void func10(int a,int b) {

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

return;

}

}

public class practice1 {

public static void main(String[] args) {

Practice t1 = new Practice();//cn cn

t1.func01();

t1.func06(3);

int b= t1.func06();

System.out.println(b);

t1.func10(1,5);

int a = t1.func10(1, 5);

System.out.println(a);

}

}