diff --git a/Conversions/Lengthconversions.php b/Conversions/Lengthconversions.php
new file mode 100644
index 00000000..64f78f56
--- /dev/null
+++ b/Conversions/Lengthconversions.php
@@ -0,0 +1,68 @@
+<?php
+
+class LengthConversions
+{
+    public static function mToKm($m)
+    {
+        if (!is_numeric($m)) {
+            throw new \InvalidArgumentException("Invalid input for mToKm: expected numeric, got string ('{$m}')");
+        }
+        return round($m / 1000, 6);
+    }
+
+    public static function kmToM($km)
+    {
+        if (!is_numeric($km)) {
+            throw new \InvalidArgumentException("Invalid input for kmToM: expected numeric, got string ('{$km}')");
+        }
+        return round($km * 1000, 6);
+    }
+
+    public static function mToMiles($m)
+    {
+        if (!is_numeric($m)) {
+            throw new \InvalidArgumentException("Invalid input for mToMiles: expected numeric, got string ('{$m}')");
+        }
+        return round($m * 0.000621373, 6);
+    }
+
+    public static function milesToM($miles)
+    {
+        if (!is_numeric($miles)) {
+            throw new \InvalidArgumentException("Invalid input for milesToM: expected numeric, got string ('{$miles}')");
+        }
+        return round($miles * 1609.34, 6);
+    }
+
+    public static function inToCm($in)
+    {
+        if (!is_numeric($in)) {
+            throw new \InvalidArgumentException("Invalid input for inToCm: expected numeric, got string ('{$in}')");
+        }
+        return round($in * 2.54, 6);
+    }
+
+    public static function cmToIn($cm)
+    {
+        if (!is_numeric($cm)) {
+            throw new \InvalidArgumentException("Invalid input for cmToIn: expected numeric, got string ('{$cm}')");
+        }
+        return round($cm * 0.3937, 6);
+    }
+
+    public static function kmToMiles($km)
+    {
+        if (!is_numeric($km)) {
+            throw new \InvalidArgumentException("Invalid input for kmToMiles: expected numeric, got string ('{$km}')");
+        }
+        return round($km * 0.621504, 6);
+    }
+
+    public static function milesToKm($miles)
+    {
+        if (!is_numeric($miles)) {
+            throw new \InvalidArgumentException("Invalid input for milesToKm: expected numeric, got string ('{$miles}')");
+        }
+        return round($miles * 1.609, 6);
+    }
+}
diff --git a/Conversions/Weightconversions.php b/Conversions/Weightconversions.php
new file mode 100644
index 00000000..dfa774fe
--- /dev/null
+++ b/Conversions/Weightconversions.php
@@ -0,0 +1,52 @@
+<?php
+
+class WeightConversions
+{
+    public static function kgToLbs($kg)
+    {
+        if (!is_numeric($kg)) {
+            throw new \InvalidArgumentException("Invalid input for kgToLbs: expected numeric, got string ('{$kg}')");
+        }
+        return round($kg * 2.20462, 5);
+    }
+
+    public static function lbsToKg($lbs)
+    {
+        if (!is_numeric($lbs)) {
+            throw new \InvalidArgumentException("Invalid input for lbsToKg: expected numeric, got string ('{$lbs}')");
+        }
+        return round($lbs * 0.453593, 5);
+    }
+
+    public static function gToKg($g)
+    {
+        if (!is_numeric($g)) {
+            throw new \InvalidArgumentException("Invalid input for gToKg: expected numeric, got string ('{$g}')");
+        }
+        return round($g / 1000, 5);
+    }
+
+    public static function kgToG($kg)
+    {
+        if (!is_numeric($kg)) {
+            throw new \InvalidArgumentException("Invalid input for kgToG: expected numeric, got string ('{$kg}')");
+        }
+        return round($kg * 1000, 5);
+    }
+
+    public static function ozToLbs($oz)
+    {
+        if (!is_numeric($oz)) {
+            throw new \InvalidArgumentException("Invalid input for ozToLbs: expected numeric, got string ('{$oz}')");
+        }
+        return round($oz * 0.0625, 5);
+    }
+
+    public static function lbsToOz($lbs)
+    {
+        if (!is_numeric($lbs)) {
+            throw new \InvalidArgumentException("Invalid input for lbsToOz: expected numeric, got string ('{$lbs}')");
+        }
+        return round($lbs * 16, 5);
+    }
+}
diff --git a/DIRECTORY.md b/DIRECTORY.md
index 18c67420..3889f1f3 100644
--- a/DIRECTORY.md
+++ b/DIRECTORY.md
@@ -16,6 +16,8 @@
   * [Octaltodecimal](./Conversions/OctalToDecimal.php)
   * [Speedconversion](./Conversions/SpeedConversion.php)
   * [Temperatureconversions](./Conversions/TemperatureConversions.php)
+  * [Weightconversions](./Conversions/Weightconversions.php)
+  * [Lengthconversions](./Conversions/Lengthconversions.php)
 
 ## Datastructures
   * Avltree
diff --git a/Searches/TwoPointers.php b/Searches/TwoPointers.php
index f05e5daa..7b8cbd21 100644
--- a/Searches/TwoPointers.php
+++ b/Searches/TwoPointers.php
@@ -46,11 +46,11 @@ function twoPointers($list, $target)
             // it means the sum is less than $target and we need to increase our sum
             // to increase the sum we will move $left pointer to the right
             $left++;
-        } else if ($list[$left] + $list[$right] > $target) {
+        } elseif ($list[$left] + $list[$right] > $target) {
             // the sum is greater than the target, so we need to decrease the sum
             // to decrease the sum we will move our $right pointer to the left
             $right--;
-        } else if ($list[$left] + $list[$right] == $target) {
+        } elseif ($list[$left] + $list[$right] == $target) {
             // if it's true, we have found a pair
             $ans++;
             // now we will move one of our pointers, otherwise it'll run forever
diff --git a/composer.json b/composer.json
index 89db6716..f049d31f 100644
--- a/composer.json
+++ b/composer.json
@@ -14,10 +14,9 @@
   },
   "require-dev": {
     "phpunit/phpunit": "^9",
-    "squizlabs/php_codesniffer": "^3.7"
+    "squizlabs/php_codesniffer": "^3.13"
   },
   "scripts": {
     "test": "vendor/bin/phpunit tests"
   }
 }
-
diff --git a/tests/Conversions/ConversionsTest.php b/tests/Conversions/ConversionsTest.php
index 93893b4e..667756f6 100644
--- a/tests/Conversions/ConversionsTest.php
+++ b/tests/Conversions/ConversionsTest.php
@@ -10,6 +10,8 @@
 require_once __DIR__ . '/../../Conversions/HexadecimalToDecimal.php';
 require_once __DIR__ . '/../../Conversions/SpeedConversion.php';
 require_once __DIR__ . '/../../Conversions/TemperatureConversions.php';
+require_once __DIR__ . '/../../Conversions/Weightconversions.php';
+require_once __DIR__ . '/../../Conversions/Lengthconversions.php';
 
 class ConversionsTest extends TestCase
 {
@@ -142,4 +144,109 @@ public function testFahrenheitToKelvin()
         $this->expectExceptionMessage('Temperature (Fahrenheit) must be a number');
         FahrenheitToKelvin("non-numeric");
     }
+    /**
+     * Helper method to test invalid input handling in conversion methods
+     *
+     * @param string $method The conversion method to test (e.g. 'WeightConversions::kgToLbs')
+     * @param mixed $value The invalid input value
+     * @param string $expectedMessage The expected exception message
+     */
+    protected function assertInvalidInputConversion($method, $value, $expectedMessage)
+    {
+        try {
+            // Call the method with the invalid input
+            $parts = explode('::', $method);
+            $className = $parts[0];
+            $methodName = $parts[1];
+            $className::$methodName($value);
+
+            // If we get here, no exception was thrown
+            $this->fail("Expected exception was not thrown for $method with invalid input");
+        } catch (InvalidArgumentException $e) {
+            // Check if the exception message matches the expected message
+            $this->assertEquals($expectedMessage, $e->getMessage());
+        }
+    }
+    public function testKgToLbs()
+    {
+        $this->assertEquals(220.462, WeightConversions::kgToLbs(100), 0.001);
+        $this->assertInvalidInputConversion('WeightConversions::kgToLbs', "invalid string", "Invalid input for kgToLbs: expected numeric, got string ('invalid string')");
+    }
+
+    public function testLbsToKg()
+    {
+        $this->assertEquals(45.3593, WeightConversions::lbsToKg(100), 0.001);
+        $this->assertInvalidInputConversion('WeightConversions::lbsToKg', "invalid string", "Invalid input for lbsToKg: expected numeric, got string ('invalid string')");
+    }
+
+    public function testGToKg()
+    {
+        $this->assertEquals(0.5, WeightConversions::gToKg(500), 0.001);
+        $this->assertInvalidInputConversion('WeightConversions::gToKg', "invalid string", "Invalid input for gToKg: expected numeric, got string ('invalid string')");
+    }
+
+    public function testKgToG()
+    {
+        $this->assertEquals(1000, WeightConversions::kgToG(1), 0.001);
+        $this->assertInvalidInputConversion('WeightConversions::kgToG', "invalid string", "Invalid input for kgToG: expected numeric, got string ('invalid string')");
+    }
+
+    public function testOzToLbs()
+    {
+        $this->assertEquals(3.5, WeightConversions::ozToLbs(56), 0.001);
+        $this->assertInvalidInputConversion('WeightConversions::ozToLbs', "invalid string", "Invalid input for ozToLbs: expected numeric, got string ('invalid string')");
+    }
+
+    public function testLbsToOz()
+    {
+        $this->assertEquals(64, WeightConversions::lbsToOz(4), 0.001);
+        $this->assertInvalidInputConversion('WeightConversions::lbsToOz', "invalid string", "Invalid input for lbsToOz: expected numeric, got string ('invalid string')");
+    }
+    public function testMToKm()
+    {
+        $this->assertEquals(1, LengthConversions::mToKm(1000), 0.001);
+        $this->assertInvalidInputConversion('LengthConversions::mToKm', "invalid string", "Invalid input for mToKm: expected numeric, got string ('invalid string')");
+    }
+
+    public function testKmToM()
+    {
+        $this->assertEquals(5000, LengthConversions::kmToM(5), 0.001);
+        $this->assertInvalidInputConversion('LengthConversions::kmToM', "invalid string", "Invalid input for kmToM: expected numeric, got string ('invalid string')");
+    }
+
+    public function testMToMiles()
+    {
+        $this->assertEquals(0.621373, LengthConversions::mToMiles(1000), 0.001);
+        $this->assertInvalidInputConversion('LengthConversions::mToMiles', "invalid string", "Invalid input for mToMiles: expected numeric, got string ('invalid string')");
+    }
+
+    public function testMilesToM()
+    {
+        $this->assertEquals(1609.34, LengthConversions::milesToM(1), 0.001);
+        $this->assertInvalidInputConversion('LengthConversions::milesToM', "invalid string", "Invalid input for milesToM: expected numeric, got string ('invalid string')");
+    }
+
+    public function testInToCm()
+    {
+        $this->assertEquals(25.4, LengthConversions::inToCm(10), 0.001);
+        $this->assertInvalidInputConversion('LengthConversions::inToCm', "invalid string", "Invalid input for inToCm: expected numeric, got string ('invalid string')");
+    }
+
+    public function testCmToIn()
+    {
+        $this->assertEquals(39.37, LengthConversions::cmToIn(100), 0.001);
+        $this->assertInvalidInputConversion('LengthConversions::cmToIn', "invalid string", "Invalid input for cmToIn: expected numeric, got string ('invalid string')");
+    }
+
+    public function testKmToMiles()
+    {
+        $this->assertEquals(6.21504, LengthConversions::kmToMiles(10), 0.001);
+        $this->assertInvalidInputConversion('LengthConversions::kmToMiles', "invalid string", "Invalid input for kmToMiles: expected numeric, got string ('invalid string')");
+    }
+
+    public function testMilesToKm()
+    {
+        $this->assertEquals(16.09, LengthConversions::milesToKm(10), 0.001);
+        $this->assertInvalidInputConversion('LengthConversions::milesToKm', "invalid string", "Invalid input for milesToKm: expected numeric, got string ('invalid string')");
+    }
 }