>進(jìn)入 echo ,print的區(qū)別在于echo 可以輸出多個(gè)變量值,而print只有一個(gè)變量,做為一個(gè)字符串輸出。 另一點(diǎn)區(qū)別在于echo 沒有返回值,print有返回值1.print不能輸出數(shù)組和對(duì)象。 print_r可以輸出stirng、in" />

国产av日韩一区二区三区精品,成人性爱视频在线观看,国产,欧美,日韩,一区,www.成色av久久成人,2222eeee成人天堂

Home php教程 php手冊(cè) PHP中echo(),print(),print

PHP中echo(),print(),print

Jun 06, 2016 pm 07:55 PM
echo linux php print Community Enter

歡迎進(jìn)入Linux社區(qū)論壇,與200萬技術(shù)人員互動(dòng)交流 >>進(jìn)入 echo ,print的區(qū)別在于echo 可以輸出多個(gè)變量值,而print只有一個(gè)變量,做為一個(gè)字符串輸出。 另一點(diǎn)區(qū)別在于echo 沒有返回值,print有返回值1.print不能輸出數(shù)組和對(duì)象。 print_r可以輸出stirng、in

歡迎進(jìn)入Linux社區(qū)論壇,與200萬技術(shù)人員互動(dòng)交流 >>進(jìn)入

  echo ,print的區(qū)別在于echo 可以輸出多個(gè)變量值,而print只有一個(gè)變量,做為一個(gè)字符串輸出。 另一點(diǎn)區(qū)別在于echo 沒有返回值,print有返回值1.print不能輸出數(shù)組和對(duì)象。

  print_r可以輸出stirng、int、float、array、object等,輸出array時(shí)會(huì)用結(jié)構(gòu)表示,print_r輸出成功時(shí)返回true;

  而且print_r可以通過print_r($str,true)來使print_r不輸出而返回 print_r處理后的值。

  可以理解為:

  print 是打印字符串

  print_r 則是打印復(fù)合類型 如數(shù)組 對(duì)象等

  在PHP中的執(zhí)行速率從快到慢為:echo(),?? print(),?? print_r()

  echo是PHP語句, print和print_r是函數(shù),語句沒有返回值,函數(shù)可以有返回值(即便沒有用)

  print()??? 只能打印出簡(jiǎn)單類型變量的值(如int,string)

  print_r() 可以打印出復(fù)雜類型變量的值(如數(shù)組,對(duì)象)

  echo???? 輸出一個(gè)或者多個(gè)字符串

  echo -- 輸出一個(gè)或者多個(gè)字符串

  Descrīption

  void echo ( string arg1 [, string …] ) //返回值為空

  echo "你好"," 朋友";

  print --輸出一個(gè)字符串

  Descrīption

  int print ( string arg )//返回值為整形

  print "你好朋友";

  可以進(jìn)行下面操作

  $name=print "nihao /n";

  $str = 'test print value is $name .';

  eval_r("/$print=/"$str/";");

  echo $print;

  print_r -- 打印關(guān)于變量的易于理解的信息。

  bool print_r ( mixed expression [, bool return] ) //返回值是布爾型的,參數(shù)是mix類型的,可以是字符串,整形,數(shù)組,對(duì)象類print_r() 顯示關(guān)于一個(gè)變量的易于理解的信息。如果給出的是 string、integer 或 float,將打印變量值本身。如果給出的是 array,將會(huì)按照一定格式顯示鍵和元素。object 與數(shù)組類似。

[1]?[2]?

PHP中echo(),print(),print

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undress AI Tool

Undress AI Tool

Undress images for free

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Hot Topics

PHP Tutorial
1502
276
Beyond the LAMP Stack: PHP's Role in Modern Enterprise Architecture Beyond the LAMP Stack: PHP's Role in Modern Enterprise Architecture Jul 27, 2025 am 04:31 AM

PHPisstillrelevantinmodernenterpriseenvironments.1.ModernPHP(7.xand8.x)offersperformancegains,stricttyping,JITcompilation,andmodernsyntax,makingitsuitableforlarge-scaleapplications.2.PHPintegrateseffectivelyinhybridarchitectures,servingasanAPIgateway

Object-Relational Mapping (ORM) Performance Tuning in PHP Object-Relational Mapping (ORM) Performance Tuning in PHP Jul 29, 2025 am 05:00 AM

Avoid N 1 query problems, reduce the number of database queries by loading associated data in advance; 2. Select only the required fields to avoid loading complete entities to save memory and bandwidth; 3. Use cache strategies reasonably, such as Doctrine's secondary cache or Redis cache high-frequency query results; 4. Optimize the entity life cycle and call clear() regularly to free up memory to prevent memory overflow; 5. Ensure that the database index exists and analyze the generated SQL statements to avoid inefficient queries; 6. Disable automatic change tracking in scenarios where changes are not required, and use arrays or lightweight modes to improve performance. Correct use of ORM requires combining SQL monitoring, caching, batch processing and appropriate optimization to ensure application performance while maintaining development efficiency.

Building Resilient Microservices with PHP and RabbitMQ Building Resilient Microservices with PHP and RabbitMQ Jul 27, 2025 am 04:32 AM

To build a flexible PHP microservice, you need to use RabbitMQ to achieve asynchronous communication, 1. Decouple the service through message queues to avoid cascade failures; 2. Configure persistent queues, persistent messages, release confirmation and manual ACK to ensure reliability; 3. Use exponential backoff retry, TTL and dead letter queue security processing failures; 4. Use tools such as supervisord to protect consumer processes and enable heartbeat mechanisms to ensure service health; and ultimately realize the ability of the system to continuously operate in failures.

Creating Production-Ready Docker Environments for PHP Creating Production-Ready Docker Environments for PHP Jul 27, 2025 am 04:32 AM

Using the correct PHP basic image and configuring a secure, performance-optimized Docker environment is the key to achieving production ready. 1. Select php:8.3-fpm-alpine as the basic image to reduce the attack surface and improve performance; 2. Disable dangerous functions through custom php.ini, turn off error display, and enable Opcache and JIT to enhance security and performance; 3. Use Nginx as the reverse proxy to restrict access to sensitive files and correctly forward PHP requests to PHP-FPM; 4. Use multi-stage optimization images to remove development dependencies, and set up non-root users to run containers; 5. Optional Supervisord to manage multiple processes such as cron; 6. Verify that no sensitive information leakage before deployment

VSCode settings.json location VSCode settings.json location Aug 01, 2025 am 06:12 AM

The settings.json file is located in the user-level or workspace-level path and is used to customize VSCode settings. 1. User-level path: Windows is C:\Users\\AppData\Roaming\Code\User\settings.json, macOS is /Users//Library/ApplicationSupport/Code/User/settings.json, Linux is /home//.config/Code/User/settings.json; 2. Workspace-level path: .vscode/settings in the project root directory

A Deep Dive into PHP's Internal Garbage Collection Mechanism A Deep Dive into PHP's Internal Garbage Collection Mechanism Jul 28, 2025 am 04:44 AM

PHP's garbage collection mechanism is based on reference counting, but circular references need to be processed by a periodic circular garbage collector; 1. Reference count releases memory immediately when there is no reference to the variable; 2. Reference reference causes memory to be unable to be automatically released, and it depends on GC to detect and clean it; 3. GC is triggered when the "possible root" zval reaches the threshold or manually calls gc_collect_cycles(); 4. Long-term running PHP applications should monitor gc_status() and call gc_collect_cycles() in time to avoid memory leakage; 5. Best practices include avoiding circular references, using gc_disable() to optimize performance key areas, and dereference objects through the ORM's clear() method.

The Serverless Revolution: Deploying Scalable PHP Applications with Bref The Serverless Revolution: Deploying Scalable PHP Applications with Bref Jul 28, 2025 am 04:39 AM

Bref enables PHP developers to build scalable, cost-effective applications without managing servers. 1.Bref brings PHP to AWSLambda by providing an optimized PHP runtime layer, supports PHP8.3 and other versions, and seamlessly integrates with frameworks such as Laravel and Symfony; 2. The deployment steps include: installing Bref using Composer, configuring serverless.yml to define functions and events, such as HTTP endpoints and Artisan commands; 3. Execute serverlessdeploy command to complete the deployment, automatically configure APIGateway and generate access URLs; 4. For Lambda restrictions, Bref provides solutions.

Building Immutable Objects in PHP with Readonly Properties Building Immutable Objects in PHP with Readonly Properties Jul 30, 2025 am 05:40 AM

ReadonlypropertiesinPHP8.2canonlybeassignedonceintheconstructororatdeclarationandcannotbemodifiedafterward,enforcingimmutabilityatthelanguagelevel.2.Toachievedeepimmutability,wrapmutabletypeslikearraysinArrayObjectorusecustomimmutablecollectionssucha

See all articles