高质量PHP代码的50个实用技巧必备（上）

require_once('../../lib/some_class.php');

view sourceprint? define('ROOT' , '/var/www/project/'); require_once(ROOT . '../../lib/some_class.php'); //rest of the code

//suppose your script is /var/www/project/index.php //Then __FILE__ will always have that full path. define('ROOT' , pathinfo(__FILE__, PATHINFO_DIRNAME)); require_once(ROOT . '../../lib/some_class.php'); //rest of the code

require_once('lib/Database.php'); require_once('lib/Mail.php'); require_once('helpers/utitlity_functions.php');

function load_class($class_name) { //path to the class file $path = ROOT . '/lib/' . $class_name . '.php'); require_once( $path ); } load_class('Database'); load_class('Mail');

function load_class($class_name) { //path to the class file $path = ROOT . '/lib/' . $class_name . '.php'); if(file_exists($path)) { require_once( $path ); } }

define('ENVIRONMENT' , 'development'); if(! $db->query( $query ) { if(ENVIRONMENT == 'development') { echo "$query failed"; } else { echo "Database error. Please contact administrator"; } }

define('ENVIRONMENT' , 'production'); if(! $db->query( $query ) { if(ENVIRONMENT == 'development') { echo "$query failed"; } else { echo "Database error. Please contact administrator"; } }

/** Method to execute a command in the terminal Uses : 1. system 2. passthru 3. exec 4. shell_exec */ function terminal($command) { //system if(function_exists('system')) { ob_start(); system($command , $return_var); $output = ob_get_contents(); ob_end_clean(); } //passthru else if(function_exists('passthru')) { ob_start(); passthru($command , $return_var); $output = ob_get_contents(); ob_end_clean(); } //exec else if(function_exists('exec')) { exec($command , $output , $return_var); $output = implode("/n" , $output); } //shell_exec else if(function_exists('shell_exec')) { $output = shell_exec($command) ; } else { $output = 'Command execution not possible on this system'; $return_var = 1; }return array('output' => $output , 'status' => $return_var); } terminal('ls');

function add_to_cart($item_id , $qty)  { $_SESSION['cart']['item_id'] = $qty; }add_to_cart( 'IPHONE3' , 2 );

function add_to_cart($item_id , $qty) { if(!is_array($item_id)) { $_SESSION['cart']['item_id'] = $qty; } else { foreach($item_id as $i_id => $qty) { $_SESSION['cart']['i_id'] = $qty; } } } add_to_cart( 'IPHONE3' , 2 ); add_to_cart( array('IPHONE3' => 2 , 'IPAD' => 5) );

<?php echo "Hello"; //Now dont close this tag

<?php class super_class { function super_function() { //super code } } ?>

require_once('super_class.php'); //echo an image or pdf , or set the cookies or session data

<?php class super_class { function super_function() { //super code } } //No closing tag

function print_header() { echo "<div id='header'>Site Log and Login links</div>"; } function print_footer() { echo "<div id='footer'>Site was made by me</div>"; } print_header(); for($i = 0 ; $i < 100; $i++) { echo "I is : $i '; }print_footer();

function print_header() { $o = "<div id='header'>Site Log and Login links</div>"; return $o; }function print_footer() { $o = "<div id='footer'>Site was made by me</div>"; return $o; }echo print_header(); for($i = 0 ; $i < 100; $i++) { echo "I is : $i '; } echo print_footer();

$xml = '<?xml version="1.0" encoding="utf-8" standalone="yes"?>'; $xml = "<response> <code>0</code> </response>";//Send xml data echo $xml;

$xml = '<?xml version="1.0" encoding="utf-8" standalone="yes"?>'; $xml = "<response> <code>0</code> </response>"; //Send xml data header("content-type: text/xml"); echo $xml;

JavaScriptheader("content-type: application/x-javascript"); echo "var a = 10"; CSSheader("content-type: text/css"); echo "#div id { background:#000; }";

//Attempt to connect to database $c = mysqli_connect($this->host , $this->username, $this->password); //Check connection validity if (!$c) { die ("Could not connect to the database host: ". mysqli_connect_error()); } //Set the character set of the connectionif(!mysqli_set_charset ( $c , 'UTF8' )) { die('mysqli_set_charset() failed'); }

$value = htmlentities($this->value , ENT_QUOTES , CHARSET);

$images = array( 'myself.png' , 'friends.png' , 'colleagues.png' );$js_code = '';foreach($images as $image){$js_code .= "'$image' ,";}$js_code = 'var images = [' . $js_code . ']; ';echo $js_code;//Output is var images = ['myself.png' ,'friends.png' ,'colleagues.png' ,];  更聪明的做法, 使用 json_encode:  $images = array( 'myself.png' , 'friends.png' , 'colleagues.png' );$js_code = 'var images = ' . json_encode($images); echo $js_code;//Output is : var images = ["myself.png","friends.png","colleagues.png"]

$contents = "All the content";$file_path = "/var/www/project/content.txt"; file_put_contents($file_path , $contents);

$contents = "All the content"; $dir = '/var/www/project'; $file_path = $dir . "/content.txt"; if(is_writable($dir)) { file_put_contents($file_path , $contents); } else { die("Directory $dir is not writable, or does not exist. Please check"); }

// Read and write for owner, read for everybody else chmod("/somedir/somefile", 0644); // Everything for owner, read and execute for others chmod("/somedir/somefile", 0755);

if($_POST['submit'] == 'Save') { //Save the things }

if( $_SERVER['REQUEST_METHOD'] == 'POST' and isset($_POST['submit']) ) { //Save the things }

//Delay for some time function delay() { $sync_delay = get_option('sync_delay'); echo "Delaying for $sync_delay seconds..."; sleep($sync_delay); echo "Done "; }

//Delay for some time function delay() { static $sync_delay = null; if($sync_delay == null) { $sync_delay = get_option('sync_delay'); } echo "Delaying for $sync_delay seconds..."; sleep($sync_delay); echo "Done "; }

$_SESSION['username'] = $username; $username = $_SESSION['username'];

define('APP_ID' , 'abc_corp_ecommerce'); //Function to get a session variable function session_get($key) { $k = APP_ID . '.' . $key; if(isset($_SESSION[$k])) { return $_SESSION[$k]; } return false; } //Function set the session variable function session_set($key , $value) { $k = APP_ID . '.' . $key; $_SESSION[$k] = $value; return true; }

function utility_a() { //This function does a utility thing like string processing }function utility_b() { //This function does nother utility thing like database processing } function utility_c() { //This function is ... }

class Utility {public static function utility_a(){}public static function utility_b() { }public static function utility_c() { } }//and call them as $a = Utility::utility_a(); $b = Utility::utility_b();

<span style="color:#333333;font-family:''Helvetica, Arial, sans-serif'';">if($a == true) $a_count++;</span>

<span style="color:#333333;font-family:''Helvetica, Arial, sans-serif'';">if($a == true) { $a_count++; }</span>

foreach($arr as $c => $v) { $arr[$c] = trim($v); }

$arr = array_map('trim' , $arr);

$amount = intval( $_GET['amount'] );$rate = (int) $_GET['rate'];

$db_records_in_array_format; //This is a big array holding 1000 rows from a table each having 20 columns , every row is atleast 100 bytes , so total 1000 * 20 * 100 = 2MB$cc = $db_records_in_array_format; //2MB moresome_function($cc); //Another 2MB ?

$a = get_large_array(); pass_to_function(&$a);

class A { function first() { $this->a = get_large_array(); $this->pass_to_function(); } function pass_to_function() { //process $this->a } }

function add_to_cart() {$db = new Database(); $db->query("INSERT INTO cart ....."); } function empty_cart() {$db = new Database(); $db->query("DELETE FROM cart ....."); }