I need to figure out how to get this result:

I got this but how to put result from 2nd loop in new line?

public class Main04 {
    public static void main(String[] args) {
        int w = 1;
        while  (w <= 10) {
            System.out.print(  w  " ");
            w  ;
        }
        for ( int f = 1; f<=10; f  )
            System.out.print( f   " ");
    }
}

CodePudding user response：

Simply call System.out.println to print a delimiting newline after the first loop:

public class Main04 {
    public static void main(String[] args) {
        int w = 1;
        while  (w <= 10) {
            System.out.print(  w  " ");
            w  ;
        }
        System.out.println(); // print delimiting newline
        for ( int f = 1; f<=10; f  )
            System.out.print( f   " ");
    }
}

Note: Currently your code will add a trailing space after the last number.

CodePudding user response：

As a slightly different approach: rather than printing each term separately, collect them in an array, and then just print each array on its own line using the Arrays.toString(...) method from java.utils.Arrays:

import java.util.Arrays;

public class Main04 {
    public static void main(String[] args) {
        // we know the length of this array
        int[] values = new int[10];

        // fill the array using a while loop
        int w = 1;
        while  (w <= 10) {
            values[w-1] = w;
            w  ;
        }

        System.out.println(Arrays.toString(values));

        // fill the array using a for loop. We know
        // we're going to fully cover the old array,
        // but just in case: throw away the old one.
        values = new int[10];

        for (int f = 1; f<=10; f  ) {
            values[f-1] = f;
        }

        System.out.println(Arrays.toString(values));
    }
}

Yielding:

[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

CodePudding user response：

You must use System.out.println(); instead of System.out.print();

Alternatively, you may append "\n" to the end of the String printed by the first loop to add a newline character.

In that case, you would want to ALSO add a "\n" to the end of the second loop's print statement and ideally, only if it is not the last iteration of the loop

public class Main04 {

    public static void main(String[] args) {
        int w = 1;
        final StringBuilder sbLoopOne = new StringBuilder();
        final StringBuilder sbLoopTwo = new StringBuilder();
        while  (w <= 10) {
         sbLoopOne.append(Integer.toString(w));
         
         //Only print space if needed
         if(w != 10) { sbLoopOne.append(" ");} 

         w  ;
        }
        for ( int f = 1; f<=10; f  ){
        sbLoopTwo.append(Integer.toString(f));
        //Only print space if needed
        if(f != 10) { sbLoopTwo.append(" ");}

        }
       System.out.println(sbLoopOne.toString());
       System.out.println(sbLoopTwo.toString());
  

    }
}

In the above example, we use StringBuilder in an effort to demonstrate knowledge of the Java compiler's inability to optimize String concatenation using the " " operator within an iterative context.

The idea is that we collect all of the characters we would like to print in StringBuilder objects and then print them afterward.