Add trim, function exists, filesize, file_get_contents

Author: BaseMax

file_get_contents.php

@@ -0,0 +1,11 @@
+<?php
+// file_get_contents
+$data = file_get_contents("array_keys.php");
+print $data;
+
+var_dump(filesize("array_keys.php"));
+
+$f = fopen("array_keys.php", "r");
+$data = fread($f, filesize("array_keys.php"));
+print $data;
+fclose($f);

filesize.php

@@ -0,0 +1,5 @@
+<?php
+// filesize
+$filename = "file_get_contents.php";
+$size = filesize($filename);
+print "$size Byte(s)\n";

function_exists.php

@@ -0,0 +1,13 @@
+<?php
+// function_exists
+function a() {
+
+}
+var_dump(function_exists("a"));
+
+var_dump(function_exists("xxxxxxx"));
+
+var_dump(function_exists("echo"));
+var_dump(function_exists("print"));
+var_dump(function_exists("return"));
+var_dump(function_exists("function_exists"));

trim.php

@@ -0,0 +1,25 @@
+<?php
+// trim
+$string = "  abcdefghijklmnopqrstuvwxyz  ";
+var_dump(trim($string));
+
+$list = [
+    "reza",
+    "ali",
+    "hamid"
+];
+$seperate = "\n";
+$str = "";
+foreach($list as $item) {
+    $str = $str . $item . $seperate;
+}
+var_dump($str);
+$str = rtrim($str, $seperate);
+var_dump($str);
+
+// ltrim
+$string = "  abcdefghijklmnopqrstuvwxyz  ";
+var_dump(ltrim($string));
+
+// rtrim
+var_dump(rtrim($string));