import java.util.*;
public class Program {
public static void main(String []args) {
Scanner in = new Scanner(System.in);
System.out.print("Enter a number: ");
int n=in.nextInt();
for(int i=1;i<=n;i++) {
for(int j=i;j<=n-1;j++) {
System.out.print(" ");
}
for(int j=1;j<=i;j++) {
System.out.print(j);
}
for(int j=i-1;j>=1;j--) {
System.out.print(j);
}
System.out.println();
}
}
}
Output:
$ java Program
Enter a number: 4
1
121
12321
1234321
Now you've had time to work this out for yourself, if you're still stuck, try something like this, which uses nested for loops. Good luck!
public class PatternMaker {
public static void main (String[] args) {
int i, j;
// outer loop counts up from 1 to 3
for (i=1; i<=3; i++) {
for (j=1; j<=i; j++) { // inner loop counts up
System.out.print(j+" ");
} // end for j
for (j=i-1; j>=1; j--) { // inner loop counts down
System.out.print(j+" ");
} // end for j
} // end for i
} // end main()
} // end class PatternMaker
System.out.println("1 1 2 1 1 2 3 2 1");
