PHP Array Exercises : Floor decimal numbers with precision

Last update on May 30 2025 13:14:06 (UTC/GMT +8 hours)

18. Floor Decimal with Precision

Write a PHP function to floor decimal numbers with precision.

Note: Accept three parameters number, precision, and $separator
Sample Data :
1.155, 2, "."
100.25781, 4, "."
-2.9636, 3, "."

Sample Solution:

PHP Code:

<?php
// Define a function named 'floorDec' that rounds down a decimal number to a specified precision using a given separator
function floorDec($number, $precision, $separator)
{
    // Split the decimal number into integer and fractional parts using the specified separator
    $number_part = explode($separator, $number);

    // Replace a portion of the fractional part to achieve the desired precision
    $number_part[1] = substr_replace($number_part[1], $separator, $precision, 0);

    // If the integer part is non-negative, use 'floor' to round down the fractional part
    if ($number_part[0] >= 0) {
        $number_part[1] = floor($number_part[1]);
    }
    // If the integer part is negative, use 'ceil' to round up the fractional part
    else {
        $number_part[1] = ceil($number_part[1]);
    }

    // Combine the modified integer and fractional parts and return the result
    $ceil_number = array($number_part[0], $number_part[1]);
    return implode($separator, $ceil_number);
}

// Call the 'floorDec' function with examples and print the results
print_r(floorDec(1.155, 2, ".") . "\n");
print_r(floorDec(100.25781, 4, ".") . "\n");
print_r(floorDec(-2.9636, 3, ".") . "\n");
?>

Output:

1.15                                                        
100.2578                                                    
-2.964

Flowchart:

For more Practice: Solve these Related Problems:

Write a PHP function that floors a decimal number to a specified precision and returns the result as a string using a custom separator.
Write a PHP script to implement a function that rounds down a number to a given number of decimal places without using round().
Write a PHP program to compare the output of your custom floor function with PHP's floor() and format the output with the specified separator.
Write a PHP function to handle negative decimal numbers and floor them to the desired precision, ensuring correct formatting.

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