오늘의 요약
(2) 반복문
-> 초기식(밖), 조건식(안), 증감식(안)를 갖추어야 '유한루프'가 들게 됨
1) while(boolean형){}
2) do{} while(boolean형);
3) for(초기식; 조건식; 증감식){}
A.java
class A
{
void m1(){
int i=3;
while(i<3){
System.out.println("while : " + i);
i++;
}
}
void m2(){
int i=3;
do{
System.out.println("do while : " + i);
i++;
}while(i<3);
}
void m3(){
for(int i=0; i<3; i++){
System.out.println("for : " + i);
}
}
public static void main(String[] args) {
A a = new A();
a.m3();
}
}
B.java
class B {
void m1(){
int sum = 0;
for(int i=1; i<=100; i++){
sum = sum + i;
}
System.out.println("sum: " + sum);
}
void m2(){
int sum1 = 0;
for (int i=0; i<=100; i+=2){
sum1 = sum1 + i;
}
System.out.println("짝수합 sum: "+ sum1);
int sum2 = 0;
for (int i=1; i<=100; i+=2){
sum2 = sum2 + i;
}
System.out.println("홀수합 sum: "+ sum2);
}
void m3(){
int jjSum = 0;
int holSum = 0;
for(int i=1; i<=100; i++){
if(i%2==1){
holSum += i;
}else{
jjSum += i;
}
}
System.out.println("jjSum: " + jjSum + ", holSum: " + holSum
+ ", totalSum: " + (jjSum + holSum));
}
public static void main(String[] args){
B b = new B();
b.m3();
}
}
C.java
class C {
C(){
}
void m1(){
for(int i=1; i<=9; i++)
System.out.println("2 * "+i+" = " + (2*i));
}
void m2(){
for(int j=2; j<=9; j++){
for(int i=1; i<=9; i++)
System.out.println(j+" * "+i+" = " + (j*i));
System.out.println();
}
}
void m3(){
for(int k=2; k<=9; k++){
for(int j=1; j<=9; j++){
for(int i=1; i<=9; i++)
System.out.println(k+" * "+j+" * "+i+" = " + (k*j*i));
System.out.println();
}
}
}
void m4(){
for(int m=2; m<=9; m++){
for(int k=2; k<=9; k++){
for(int j=1; j<=9; j++){
for(int i=1; i<=9; i++)
System.out.println(m+" * "+k+" * "+j+" * "+i+" = " + (m*k*j*i));
System.out.println();
}
}
}
}
void m5(){
int m=2;
while(m<=9){
int k=2;
while(k<=9){
int j=1;
while(j<=9){
int i=1;
while(i<=9){
System.out.println(m+" * "+k+" * "+j+" * "+i+" = " + (m*k*j*i));
i++;
}
System.out.println();
j++;
}
k++;
}
m++;
}
}
public static void main(String[] args){
C c = new C();
c.m5();
}
}