1-1000 the sum of the number of conventions = itself
public class demo1{
public static void Main (string[] args) {
for (int i=1;i<1000;i++) {
int sum=0;
for (int j=1;j<i;j++) {
if (i%j==0) {
Sum +=j;
}
}
if (sum==i) {
System.out.println (i);
}
}
}
}
2. tab 5 rows 5 rows multiplied by 10 by 100 columns in turn
public class Demo19 {
public static void Main (string[] args) {
System.out.println ("N" + "\ T" + "10*n" + "\ T" + "100*n" + "\ T" + "1000*n");
for (int i=1;i<=5;i++) {
int sum=1;
for (int j=0;j<=3;j++) {
Sum*=10;
System.out.print (i*sum+ "\ t");
}
System.out.println ();
}
}
}
3. Enter a number, this number multiplication table
public class Demo2 {
public static void Main (string[] args) {
Scanner input=new Scanner (system.in);
System.out.println ("Please enter a number:");
int Num=input.nextint ();
for (int i = 1; I <=num; i++) {
for (int j = 1; J <=i; J + +) {
System.out.print (j+ "*" +i+ "=" +i*j);
System.out.print (' \ t ');
}
System.out.println ();
}
}
}
Classic Loops in Java