PHP for loop Exercises: Using nested for loop, construct a specific pattern

Last update on May 31 2025 12:58:04 (UTC/GMT +8 hours)

4. Construct Symmetric Star Pattern

Create a script to construct the following pattern, using a nested for loop.

* 
* * 
* * * 
* * * * 
* * * * * 
* * * * * 
* * * * 
* * * 
* * 
*

Visual Presentation:

PHP for loop Exercises: Using nested for loop, construct a specific pattern

Sample Solution:

PHP Code:

<?php
// Define the number of rows
$n = 5;

// Loop to print the upper half of the diamond
for($i=1; $i<=$n; $i++)
{
    // Loop to print the spaces and stars for each row
    for($j=1; $j<=$i; $j++)
    {
        // Print a star surrounded by spaces
        echo ' * ';
    }
    // Move to the next line after printing each row
    echo '\n';
}

// Loop to print the lower half of the diamond
for($i=$n; $i>=1; $i--)
{
    // Loop to print the spaces and stars for each row
    for($j=1; $j<=$i; $j++)
    {
        // Print a star surrounded by spaces
        echo ' * ';
    }
    // Move to the next line after printing each row
    echo '\n ';
}
?>

Output:

 *                                                          
 *  *                                                       
 *  *  *                                                    
 *  *  *  *                                                 
 *  *  *  *  *                                              
 *  *  *  *  *                                              
 *  *  *  *                                                 
 *  *  *                                                    
 *  *                                                       
 *

Explanation:

In the exercise above,

The code starts with a PHP opening tag <?php.
It defines a variable '$n' and sets its value to 5, which represents the number of rows in the diamond pattern.
The code then enters a loop to print the upper half of the diamond. This loop iterates from 1 to the value of '$n'.
Inside the loop, there's another loop responsible for printing the spaces and stars for each row. It iterates from 1 to the current row number.
Within this inner loop, a star surrounded by spaces (' * ') is echoed for each iteration.
After printing all the spaces and stars for a row, a newline character (\n) is echoed to move to the next line.
Once the upper half of the diamond is printed, the code enters another loop to print the lower half. This loop iterates from the value of '$n' down to 1.
Inside this loop, the same process repeats: printing spaces and stars for each row, followed by moving to the next line.
However, notice that extra space is printed after each line in the lower half of the diamond (echo '\n ';). This might be a typo or unintended behavior, as it seems to introduce additional space at the end of each line.
Finally, PHP code ends with a closing tag ?>.

Flowchart :

For more Practice: Solve these Related Problems:

Write a PHP script to print a symmetric star pattern that increases to a maximum row and then decreases symmetrically using nested loops.
Write a PHP function to generate a diamond-like star pattern where the middle row is repeated twice.
Write a PHP program that uses nested loops to create an hourglass star pattern with a specified number of rows.
Write a PHP script that constructs a mirror star pattern, ensuring the top and bottom halves are exact reflections.

Go to:

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PHP Code Editor:

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