diff --git a/README.md b/README.md
index f9d9c2e..f504837 100644
--- a/README.md
+++ b/README.md
@@ -1,44 +1,44 @@
 # PHP-Performance
+
 PHP Performance Measuring
 
-This Project is for some PHP Peformance measuring tests in different scopes.
-100 % is the best.
-If you have some intresting Perfomance measurings, please extend this project :-)
+This project contains several PHP performance measuring tests in different scopes.
+100.0% represents the best performance.
 
-https://phpsandbox.io/n/performance-strrpos-vs-strpos-substr-compare-vs-posvs-preg-match-op6yr
+## Prerequisites
 
-PHP 8.0:
-```
-100.0% 0.36413s strrpos()
-110.9% 0.40368s strrpos(+pos)
-116.3% 0.42361s [x]===':'
-121.9% 0.44401s strpos()
-144.6% 0.52642s substr_compare()
-155.4% 0.56575s strpos(+pos)
-256.2% 0.93287s preg_match
-```
-https://phpsandbox.io/n/performancetest-isset-vs-vs-ignoringerror-a6gaa
+- PHP >= 7.0
+- `bcmath` extension (used for precision in performance reporting)
 
-PHP 8.0:
-```
-100.0% 0.02643s isset()
-112.4% 0.02969s ??
-944.9% 0.24970s No Check
-```
+## Available Benchmarks
 
-https://phpsandbox.io/n/differenceand-performance-between-str-replace-vs-strtr-mmrck
-PHP 8.0:
-```
-str_replace:
-ZbcZZZZbcZZZZbcZZZZbcZZZZbcZZZZbcZZZZbcZZZZbcZZZZbcZZZZbcZZZ
-strtr:
-ZbcyzaZbcyzaZbcyzaZbcyzaZbcyzaZbcyzaZbcyzaZbcyzaZbcyzaZbcyza
-100.0% 0.02024s strtr()
-179.4% 0.03631s str_replace()
-str_replace:
-ZbcaaaZbcaaaZbcaaaZbcaaaZbcaaaZbcaaaZbcaaaZbcaaaZbcaaaZbcaaa
-strtr:
-ZbcyzaZbcyzaZbcyzaZbcyzaZbcyzaZbcyzaZbcyzaZbcyzaZbcyzaZbcyza
-100.0% 0.02041s strtr()
-138.8% 0.02833s str_replace()
+### 1. Timestamp Detection (`is_timestamp.php`)
+Compares different ways to find a colon in a string (simulating part of a timestamp validation).
+- `strrpos()`
+- `strpos()`
+- `substr_compare()`
+- Direct index access `[x]===':'`
+- `preg_match`
+
+### 2. Property/Array Access Checks (`property_is_set.php`)
+Compares different ways to check if an array key is set.
+- `isset()`
+- Null coalescing operator `??`
+- No check (ignoring errors)
+
+### 3. String Replacement (`str_replace_vs_strtr.php`)
+Compares performance and behavior differences between `str_replace()` and `strtr()`.
+
+## How to Run
+
+You can run any benchmark directly using the PHP CLI:
+
+```bash
+php is_timestamp.php
+php property_is_set.php
+php str_replace_vs_strtr.php
 ```
+
+## Contributing
+
+If you have interesting performance measurements, please feel free to extend this project!
diff --git a/composer.json b/composer.json
index ba94334..fb1f0c4 100644
--- a/composer.json
+++ b/composer.json
@@ -2,6 +2,6 @@
     "name": "fglueck/perf",
     "description": "Performance measuring PHP Class",
     "require": {
-        "php": ">=7.0",
+        "php": ">=7.0"
     }
 }
diff --git a/is_timestamp.php b/is_timestamp.php
index a782a1a..df6f0a1 100644
--- a/is_timestamp.php
+++ b/is_timestamp.php
@@ -1,3 +1,4 @@
+<?php
 # https://phpsandbox.io/n/performance-strrpos-vs-strpos-substr-compare-vs-posvs-preg-match-op6yr
 #error_reporting (0);
 
@@ -45,28 +46,28 @@ public function test(string $label, callable $call) {
 $p = new perf(1000000);
 
 $p->test('strrpos()', function () use ($string) {
-    if(strrpos($string, ':'));
+    if(strrpos($string, ':') !== false);
 });
 
 $p->test('strrpos(+pos)', function () use ($string) {
-    if(strrpos($string, ':', -4));
+    if(strrpos($string, ':', -4) !== false);
 });
 
 $p->test('strpos()', function () use ($string) {
-    if(strpos($string, ':'));
+    if(strpos($string, ':') !== false);
 });
 
 $p->test('strpos(+pos)', function () use ($string) {
-    if(strpos($string, ':', 12));
+    if(strpos($string, ':', 12) !== false);
 });
 
 $p->test('substr_compare()', function () use ($string) {
-    if(substr_compare($string, ':', -3,1)===1);
+    if(substr_compare($string, ':', -3,1)===0);
 });
 
 $len = strlen($string);
 $p->test("[x]===':'", function () use ($string, $len) {
-    if($len-3>0 and $string[$len-3]===':');
+    if($len-3>=0 and $string[$len-3]===':');
 });
 
 $p->test('preg_match', function () use ($string) {
diff --git a/poperty_is_set.php b/property_is_set.php
similarity index 97%
rename from poperty_is_set.php
rename to property_is_set.php
index 8598627..8629e3a 100644
--- a/poperty_is_set.php
+++ b/property_is_set.php
@@ -39,7 +39,7 @@ public function report() {
 
 $p->start();
 for($i=1000000;$i;$i--) {
-    if($x->y['']??''!=='');
+    if(($x->y['']??'') !=='');
 }
 $p->stop('??');
 $p->report();