[Closest value operator] Get closest value (of an array) before a given one #php #operand

getClosestLowerValue.php

<?php
	function valueExpected ($analyse, $expect, $strict = false)
	{
		if ($strict)
		{
			if ($analyse === $expect)
			{
				return '<span style="background-color:darkolivegreen; color:darkgrey;">Received : ' .
				       $analyse .
				       ', Expected : ' .
				       $expect .
				       ' > Test->Passed</span>';
			}
		}
		if (!$strict)
		{
			if ($analyse == $expect)
			{
				return '<span style="background-color:darkolivegreen; color:darkgrey;">Received : ' .
				       $analyse .
				       ', Expected : ' .
				       $expect .
				       ' > Test->Passed</span>';
			}
		}

		return '<span style="background-color:lightcoral; color:black;">Received : ' .
		       $analyse .
		       ', Expected : ' .
		       $expect .
		       ' > Test->Failed</span>';
	}

	function getClosestLowerValue ($search, $haystack)
	{
		$closest = null;
		$testStack = $haystack;
		$TotalLoop = count($testStack);
		//Removed higher value again tested value in $testStack
		for ($i = 0; $TotalLoop > $i; $i++)
		{
			if ($testStack[ $i ] > $search)
			{
				unset($testStack[ $i ]);
			}
		}
		//If no value left in $testStack, rerun function with a search greater by twelve (searching for month) to move position on "infinite timeline"
		if (empty($testStack))
		{
			$search = $search + 12;

			return getClosestLowerValue($search, $haystack);
		}
		else
		{
			//Since $testStack was not empty, we asume that maybe some key been removed, so we reassign position for a clean for loop.
			$haystack = array_values($testStack);
			$TotalLoop = count($haystack);
			//Search for the nearest value
			for ($i = 0; $TotalLoop > $i; $i++)
			{
				if ($closest === null || abs($search - $closest) > abs($haystack[ $i ] - $search))
				{
					$closest = $haystack[ $i ];
				}
			}

			return $closest;
		}
	}

	echo 'Testing 01 > ' . valueExpected(getClosestLowerValue(1, array (1, 5, 9, 12)), 1) . '<br>';
	echo 'Testing 02 > ' . valueExpected(getClosestLowerValue(2, array (1, 5, 9, 12)), 1) . '<br>';
	echo 'Testing 03 > ' . valueExpected(getClosestLowerValue(3, array (1, 5, 9, 12)), 1) . '<br>';
	echo 'Testing 04 > ' . valueExpected(getClosestLowerValue(4, array (1, 5, 9, 12)), 1) . '<br>';
	echo 'Testing 05 > ' . valueExpected(getClosestLowerValue(5, array (1, 5, 9, 12)), 5) . '<br>';
	echo 'Testing 06 > ' . valueExpected(getClosestLowerValue(6, array (1, 5, 9, 12)), 5) . '<br>';
	echo 'Testing 07 > ' . valueExpected(getClosestLowerValue(7, array (1, 5, 9, 12)), 5) . '<br>';
	echo 'Testing 08 > ' . valueExpected(getClosestLowerValue(8, array (1, 5, 9, 12)), 5) . '<br>';
	echo 'Testing 09 > ' . valueExpected(getClosestLowerValue(9, array (1, 5, 9, 12)), 9) . '<br>';
	echo 'Testing 10 > ' . valueExpected(getClosestLowerValue(10, array (1, 5, 9, 12)), 9) . '<br>';
	echo 'Testing 11 > ' . valueExpected(getClosestLowerValue(11, array (1, 5, 9, 12)), 9) . '<br>';
	echo 'Testing 12 > ' . valueExpected(getClosestLowerValue(12, array (1, 5, 9, 12)), 12) . '<br>';