JAVA-for循环

for循环

public class forDemo1 {
public static void main(String[] args) {
for (int i = 0; i < 100; i++) {
System.out.println(i);
}
}
}

100以内奇数偶数和和

public class forDemo2 {
public static void main(String[] args) {
//0到100奇数和偶数的和
int oddSum = 0;
int eveSum = 0;
for (int i = 0; i <= 100; i++) {
if (i % 2 == 0) {
oddSum += i;
} else {
eveSum += i;
}
}
System.out.println("奇数的和为："+oddSum);
System.out.println("偶数的和为："+eveSum);
System.out.println("总和为："+oddSum+eveSum);
}
}

用while或for循环输出1-1000之间能被5整除的数，并且每行输出3个

public class forDemo3 {
public static void main(String[] args) {
//用while或for循环输出1-1000之间能被5整除的数，并且每行输出3个
for (int i = 0; i <=1000; i++) {
if(i%5==0)
{
System.out.print(i+"\t");
}
if(i%15==0){
System.out.println();
//System.out.println("/n");
}
}
System.out.println("============================");
int a=0;
while (a<=1000){
a++;
if(a%5==0){
System.out.print(a+"\t");
}
if(a%15==0){
System.out.println();
}
}
}
}

打印九九乘法表

public class forDemo4 {
public static void main(String[] args) {
for (int i = 1; i <=9; i++) {
for (int j = 1; j <= i; j++) {
System.out.print(i+"*"+j+"="+(i*j)+"\t");
}
System.out.println();

}
}
}

遍历数组元素

public class forDemo5 {
public static void main(String[] args) {
int[] number={1,2,3,4,5};
for (int x:number) {
System.out.println(x);
}
}
}

打印三角形

public class LabeDemo1 {
public static void main(String[] args) {
//打印三角形 5行
for (int i = 1; i <= 5; i++) {
for (int j = 5; j >=i ; j--) {
System.out.print(" ");
}
for(int j=1;j<=i;j++){
System.out.print("*");
}
for(int j =1;j<i;j++){
System.out.print("*");
}
System.out.println();
}
}
}