Introduction to Loop Printing in Different Programming Languages

The task of printing numbers from 1 to 10 and then from 10 to 1 in different programming paradigms can be approached in several ways. This article explores these methods using Java, PL/I, C, and C with loops.

1. Approach in Java Using a For Loop

In Java, we can achieve this task using a for loop. However, the original code snippet has some syntax issues, including missing curly braces and incorrect usage of semicolons. Below is a corrected version that accomplishes the task:

public class PrintNumbers {    public static void main(String[] args) {        int i;        for (i  1; i  1; i--) {            (i   " ");        }        (i);    }}

This Java code prints numbers from 1 to 10, followed by 10 to 1, with an appropriate spacing and formatting for readability.

2. Approach in PL/I Using PROCEDURE

In PL/I, the looping construct can be used in a more structured way. The following PL/I code accomplishes the task of printing numbers from 1 to 10 and 10 to 1:

LOOP101: PROC OPTIONS(MAIN);  DCL LOOP FIXED BIN(31) INIT(0);  DO LOOP  1 TO 10;    PUTO(NEWLINE);  END;  DO LOOP  10 TO 1 BY -1;    PUTO(NEWLINE);  END;END LOOP101;

This PL/I code uses a loop to print numbers from 1 to 10 first, then from 10 to 1, with each number printed on a new line.

3. Approach in C Using While Loop and Subtraction

Another approach is to use a single loop and a subtraction trick in C to print numbers from 1 to 10 and 10 to 1. This example employs the C programming language:

#include int main() {    int i, M  10;    for (i  1; i  1; i--) {        printf("%d ", M - (M - i));    }    return 0;}

Here, the equation ( y 11 - x ) is used to print numbers side by side, but with adjustments to ensure correct ordering.

4. Additional Method in C Using For Loop with Reverse Calculation

An alternative method in C is to use a for loop to calculate the reverse values and print them. Here is another example in C:

#include #include int main() {    int i, M  10;    for (i  1; i 

This approach calculates the reverse values and prints them in a side-by-side format.

Hints and Tips

To solve this problem, consider the following hints:

Print numbers side by side by calculating the reverse value using the equation ( y 11 - x ). Adjust the code to handle the transition from 10 to 1 properly. Ensure that each number is printed in a readable and consistent format.

Conclusion

Printing numbers from 1 to 10 and 10 to 1 can be accomplished in various ways using different programming languages and paradigms. Whether you choose a for loop in Java, a do-while loop in C, or a structured approach in PL/I, the key is to ensure correct formatting and readability for the output.