1<?php 2$_SERVER['BASE_PAGE'] = 'releases/8.0/zh.php'; 3include_once __DIR__ . '/common.php'; 4 5releases\php80\common_header( 6 'PHP 8.0 是 PHP 语言的一次重大更新。它包含了很多新功能与优化项，' . 7 '包括命名参数、联合类型、注解、构造器属性提升、match 表达式、' . 8 'Nullsafe 运算符、JIT，并改进了类型系统、错误处理、语法一致性。'); 9 10?> 11<section class="php8-section php8-section_dark php8-section_header center"> 12 <div class="page-tools"> 13 <div class="change-language"> 14 <?php releases\php80\language_chooser('zh'); ?> 15 </div> 16 </div> 17 <div class="php8-section__content"> 18 <div class="php8-logo"> 19 <img src="/images/php8/logo_php8.svg" alt="php8" height="126" width="343"> 20 </div> 21 <div class="php8-title">已发布！</div> 22 <div class="php8-subtitle"> 23 PHP 8.0 是 PHP 语言的一次重大更新。 24 <br class="display-none-md"> 它包含了很多新功能与优化项， 25 包括命名参数、联合类型、注解、构造器属性提升、match 表达式、nullsafe 运算符、JIT，并改进了类型系统、错误处理、语法一致性。 26 </div> 27 <div class="php8-button-wrapper center"> 28 <a class="php8-button php8-button_light" href="/downloads">更新到 PHP 8！</a> 29 </div> 30 </div> 31</section> 32 33<section class="php8-section center"> 34 <div class="php8-compare"> 35 <h2 class="php8-h2" id="named-arguments"> 36 命名参数 37 <a class="php8-rfc" href="https://wiki.php.net/rfc/named_params">RFC</a> 38 </h2> 39 <div class="php8-compare__main"> 40 <div class="php8-compare__block example-contents"> 41 <div class="php8-compare__label">PHP 7</div> 42 <div class="php8-code phpcode"> 43 <?php highlight_php_trimmed( 44 'htmlspecialchars($string, ENT_COMPAT | ENT_HTML401, \'UTF-8\', false);', 45 );?> 46 </div> 47 48 49 </div> 50 <div class="php8-compare__arrow"></div> 51 <div class="php8-compare__block example-contents"> 52 <div class="php8-compare__label php8-compare__label_new">PHP 8</div> 53 <div class="php8-code phpcode"> 54 <?php highlight_php_trimmed( 55 'htmlspecialchars($string, double_encode: false);', 56 );?> 57 </div> 58 </div> 59 </div> 60 <div class="php8-compare__content"> 61 <ul> 62 <li>仅仅指定必填参数，跳过可选参数。</li> 63 <li>参数的顺序无关、自己就是文档（self-documented）</li> 64 </ul> 65 </div> 66 </div> 67 68 <div class="php8-compare"> 69 <h2 class="php8-h2" id="attributes"> 70 注解 71 <a class="php8-rfc" href="https://wiki.php.net/rfc/attributes_v2">RFC</a> <a class="php8-rfc" href="/manual/zh/language.attributes.php">Doc</a> 72 </h2> 73 <div class="php8-compare__main"> 74 <div class="php8-compare__block example-contents"> 75 <div class="php8-compare__label">PHP 7</div> 76 <div class="php8-code phpcode"> 77 <?php highlight_php_trimmed( 78 'class PostsController 79{ 80 /** 81 * @Route("/api/posts/{id}", methods={"GET"}) 82 */ 83 public function get($id) { /* ... */ } 84}', 85 );?> 86 </div> 87 </div> 88 <div class="php8-compare__arrow"></div> 89 <div class="php8-compare__block example-contents"> 90 <div class="php8-compare__label php8-compare__label_new">PHP 8</div> 91 <div class="php8-code phpcode"> 92 <?php highlight_php_trimmed( 93 'class PostsController 94{ 95 #[Route("/api/posts/{id}", methods: ["GET"])] 96 public function get($id) { /* ... */ } 97}', 98 );?> 99 </div> 100 </div> 101 </div> 102 <div class="php8-compare__content"> 103 <p>现在可以用 PHP 原生语法来使用结构化的元数据，而非 PHPDoc 声明。</p> 104 </div> 105 </div> 106 107 <div class="php8-compare"> 108 <h2 class="php8-h2" id="constructor-property-promotion"> 109 构造器属性提升 110 <a class="php8-rfc" href="https://wiki.php.net/rfc/constructor_promotion">RFC</a> <a class="php8-rfc" href="/manual/zh/language.oop5.decon.php#language.oop5.decon.constructor.promotion">文档</a> 111 </h2> 112 <div class="php8-compare__main"> 113 <div class="php8-compare__block example-contents"> 114 <div class="php8-compare__label">PHP 7</div> 115 <div class="php8-code phpcode"> 116 <?php highlight_php_trimmed( 117 'class Point { 118 public float $x; 119 public float $y; 120 public float $z; 121 public function __construct( 122 float $x = 0.0, 123 float $y = 0.0, 124 float $z = 0.0 125 ) { 126 $this->x = $x; 127 $this->y = $y; 128 $this->z = $z; 129 } 130}', 131 );?> 132 </div> 133 </div> 134 <div class="php8-compare__arrow"></div> 135 <div class="php8-compare__block example-contents"> 136 <div class="php8-compare__label php8-compare__label_new">PHP 8</div> 137 <div class="php8-code phpcode"> 138 <?php highlight_php_trimmed( 139 'class Point { 140 public function __construct( 141 public float $x = 0.0, 142 public float $y = 0.0, 143 public float $z = 0.0, 144 ) {} 145}', 146 );?> 147 </div> 148 </div> 149 </div> 150 <div class="php8-compare__content"> 151 <p>更少的样板代码来定义并初始化属性。</p> 152 </div> 153 </div> 154 155 <div class="php8-compare"> 156 <h2 class="php8-h2" id="union-types"> 157 联合类型 158 <a class="php8-rfc" href="https://wiki.php.net/rfc/union_types_v2">RFC</a> <a class="php8-rfc" href="/manual/zh/language.types.declarations.php#language.types.declarations.composite.union">文档</a> 159 </h2> 160 <div class="php8-compare__main"> 161 <div class="php8-compare__block example-contents"> 162 <div class="php8-compare__label">PHP 7</div> 163 <div class="php8-code phpcode"> 164 <?php highlight_php_trimmed( 165 'class Number { 166 /** @var int|float */ 167 private $number; 168 /** 169 * @param float|int $number 170 */ 171 public function __construct($number) { 172 $this->number = $number; 173 } 174} 175new Number(\'NaN\'); // Ok', 176 );?> 177 </div> 178 </div> 179 <div class="php8-compare__arrow"></div> 180 <div class="php8-compare__block example-contents"> 181 <div class="php8-compare__label php8-compare__label_new">PHP 8</div> 182 <div class="php8-code phpcode"> 183 <?php highlight_php_trimmed( 184 'class Number { 185 public function __construct( 186 private int|float $number 187 ) {} 188} 189new Number(\'NaN\'); // TypeError', 190 );?> 191 </div> 192 </div> 193 </div> 194 <div class="php8-compare__content"> 195 <p>相较于以前的 PHPDoc 声明类型的组合， 196 现在可以用原生支持的联合类型声明取而代之，并在运行时得到校验。</p> 197 </div> 198 </div> 199 200 <div class="php8-compare"> 201 <h2 class="php8-h2" id="match-expression"> 202 Match 表达式 203 <a class="php8-rfc" href="https://wiki.php.net/rfc/match_expression_v2">RFC</a> <a class="php8-rfc" href="/manual/zh/control-structures.match.php">文档</a> 204 </h2> 205 <div class="php8-compare__main"> 206 <div class="php8-compare__block example-contents"> 207 <div class="php8-compare__label">PHP 7</div> 208 <div class="php8-code phpcode"> 209 <?php highlight_php_trimmed( 210 'switch (8.0) { 211 case \'8.0\': 212 $result = "Oh no!"; 213 break; 214 case 8.0: 215 $result = "This is what I expected"; 216 break; 217} 218echo $result; 219//> Oh no!', 220 );?> 221 </div> 222 </div> 223 <div class="php8-compare__arrow"></div> 224 <div class="php8-compare__block example-contents"> 225 <div class="php8-compare__label php8-compare__label_new">PHP 8</div> 226 <div class="php8-code phpcode"> 227 <?php highlight_php_trimmed( 228 'echo match (8.0) { 229 \'8.0\' => "Oh no!", 230 8.0 => "This is what I expected", 231}; 232//> This is what I expected', 233 );?> 234 </div> 235 </div> 236 </div> 237 <div class="php8-compare__content"> 238 <p>新的 match 类似于 switch，并具有以下功能：</p> 239 <ul> 240 <li>Match 是一个表达式，它可以储存到变量中亦可以直接返回。</li> 241 <li>Match 分支仅支持单行，它不需要一个 break; 语句。</li> 242 <li>Match 使用严格比较。</li> 243 </ul> 244 </div> 245 </div> 246 247 <div class="php8-compare"> 248 <h2 class="php8-h2" id="nullsafe-operator"> 249 Nullsafe 运算符 250 <a class="php8-rfc" href="https://wiki.php.net/rfc/nullsafe_operator">RFC</a> 251 </h2> 252 <div class="php8-compare__main"> 253 <div class="php8-compare__block example-contents"> 254 <div class="php8-compare__label">PHP 7</div> 255 <div class="php8-code phpcode"> 256 <?php highlight_php_trimmed( 257 '$country = null; 258if ($session !== null) { 259 $user = $session->user; 260 if ($user !== null) { 261 $address = $user->getAddress(); 262 263 if ($address !== null) { 264 $country = $address->country; 265 } 266 } 267}', 268 );?> 269 </div> 270 </div> 271 <div class="php8-compare__arrow"></div> 272 <div class="php8-compare__block example-contents"> 273 <div class="php8-compare__label php8-compare__label_new">PHP 8</div> 274 <div class="php8-code phpcode"> 275 <?php highlight_php_trimmed( 276 '$country = $session?->user?->getAddress()?->country;', 277 );?> 278 </div> 279 </div> 280 </div> 281 <div class="php8-compare__content"> 282 <p>现在可以用新的 nullsafe 运算符链式调用，而不需要条件检查 null。 283 如果链条中的一个元素失败了，整个链条会中止并认定为 Null。</p> 284 </div> 285 </div> 286 287 <div class="php8-compare"> 288 <h2 class="php8-h2" id="saner-string-to-number-comparisons"> 289 字符串与数字的比较更符合逻辑 290 <a class="php8-rfc" href="https://wiki.php.net/rfc/string_to_number_comparison">RFC</a> 291 </h2> 292 <div class="php8-compare__main"> 293 <div class="php8-compare__block example-contents"> 294 <div class="php8-compare__label">PHP 7</div> 295 <div class="php8-code phpcode"> 296 <?php highlight_php_trimmed( 297 '0 == \'foobar\' // true', 298 );?> 299 </div> 300 </div> 301 <div class="php8-compare__arrow"></div> 302 <div class="php8-compare__block example-contents"> 303 <div class="php8-compare__label php8-compare__label_new">PHP 8</div> 304 <div class="php8-code phpcode"> 305 <?php highlight_php_trimmed( 306 '0 == \'foobar\' // false', 307 );?> 308 </div> 309 </div> 310 </div> 311 <div class="php8-compare__content"> 312 <p>PHP 8 比较数字字符串（numeric string）时，会按数字进行比较。 313 不是数字字符串时，将数字转化为字符串，按字符串比较。</p> 314 </div> 315 </div> 316 317 <div class="php8-compare"> 318 <h2 class="php8-h2" id="consistent-type-errors-for-internal-functions"> 319 内部函数类型错误的一致性。 320 <a class="php8-rfc" href="https://wiki.php.net/rfc/consistent_type_errors">RFC</a> 321 </h2> 322 <div class="php8-compare__main"> 323 <div class="php8-compare__block example-contents"> 324 <div class="php8-compare__label">PHP 7</div> 325 <div class="php8-code phpcode"> 326 <?php highlight_php_trimmed( 327 'strlen([]); // Warning: strlen() expects parameter 1 to be string, array given 328array_chunk([], -1); // Warning: array_chunk(): Size parameter expected to be greater than 0', 329 );?> 330 </div> 331 </div> 332 <div class="php8-compare__arrow"></div> 333 <div class="php8-compare__block example-contents"> 334 <div class="php8-compare__label php8-compare__label_new">PHP 8</div> 335 <div class="php8-code phpcode"> 336 <?php highlight_php_trimmed( 337 'strlen([]); // TypeError: strlen(): Argument #1 ($str) must be of type string, array given 338array_chunk([], -1); // ValueError: array_chunk(): Argument #2 ($length) must be greater than 0', 339 );?> 340 </div> 341 </div> 342 </div> 343 <div class="php8-compare__content"> 344 <p>现在大多数内部函数在参数验证失败时抛出 Error 级异常。</p> 345 </div> 346 </div> 347</section> 348 349<section class="php8-section php8-section_light"> 350 <h2 class="php8-h2">即时编译</h2> 351 <p> 352 PHP 8 引入了两个即时编译引擎。 353 Tracing JIT 在两个中更有潜力，它在综合基准测试中显示了三倍的性能， 354 并在某些长时间运行的程序中显示了 1.5-2 倍的性能改进。 355 典型的应用性能则和 PHP 7.4 不相上下。 356 </p> 357 <h3 class="php8-h3"> 358 关于 JIT 对 PHP 8 性能的贡献 359 </h3> 360 <p> 361 <img src="/images/php8/scheme.svg" width="900" alt="Just-In-Time compilation"> 362 </p> 363 364 <div class="php8-columns"> 365 <div class="php8-column"> 366 <h2 class="php8-h2 php8-h2_margin-top">类型系统与错误处理的改进</h2> 367 <ul> 368 <li> 369 算术/位运算符更严格的类型检测 370 <a href="https://wiki.php.net/rfc/arithmetic_operator_type_checks">RFC</a> 371 </li> 372 <li> 373 Abstract trait 方法的验证 <a href="https://wiki.php.net/rfc/abstract_trait_method_validation">RFC</a> 374 </li> 375 <li> 376 确保魔术方法签名正确 <a href="https://wiki.php.net/rfc/magic-methods-signature">RFC</a> 377 </li> 378 <li> 379 PHP 引擎 warning 警告的重新分类 <a href="https://wiki.php.net/rfc/engine_warnings">RFC</a> 380 </li> 381 <li> 382 不兼容的方法签名导致 Fatal 错误 <a href="https://wiki.php.net/rfc/lsp_errors">RFC</a> 383 </li> 384 <li> 385 操作符 @ 不再抑制 fatal 错误。 386 </li> 387 <li> 388 私有方法继承 <a href="https://wiki.php.net/rfc/inheritance_private_methods">RFC</a> 389 </li> 390 <li> 391 Mixed 类型 <a href="https://wiki.php.net/rfc/mixed_type_v2">RFC</a> 392 </li> 393 <li> 394 Static 返回类型 <a href="https://wiki.php.net/rfc/static_return_type">RFC</a> 395 </li> 396 <li> 397 内部函数的类型 398 <a href="https://externals.io/message/106522">Email thread</a> 399 </li> 400 <li> 401 扩展 402 <a href="https://php.watch/versions/8.0/resource-CurlHandle">Curl</a>、 403 <a href="https://php.watch/versions/8.0/gdimage">Gd</a>、 404 <a href="https://php.watch/versions/8.0/sockets-sockets-addressinfo">Sockets</a>、 405 <a href="https://php.watch/versions/8.0/OpenSSL-resource">OpenSSL</a>、 406 <a href="https://php.watch/versions/8.0/xmlwriter-resource">XMLWriter</a>、 407 <a href="https://php.watch/versions/8.0/xmlwriter-resource">XML</a> 408 以 Opaque 对象替换 resource。 409 </li> 410 </ul> 411 </div> 412 <div class="php8-column"> 413 <h2 class="php8-h2 php8-h2_margin-top">其他语法调整和改进</h2> 414 <ul> 415 <li> 416 允许参数列表中的末尾逗号 <a href="https://wiki.php.net/rfc/trailing_comma_in_parameter_list">RFC</a>、 417 闭包 use 列表中的末尾逗号 <a href="https://wiki.php.net/rfc/trailing_comma_in_closure_use_list">RFC</a> 418 </li> 419 <li> 420 无变量捕获的 catch <a href="https://wiki.php.net/rfc/non-capturing_catches">RFC</a> 421 </li> 422 <li> 423 变量语法的调整 <a href="https://wiki.php.net/rfc/variable_syntax_tweaks">RFC</a> 424 </li> 425 <li> 426 Namespace 名称作为单个 token <a href="https://wiki.php.net/rfc/namespaced_names_as_token">RFC</a> 427 </li> 428 <li> 429 现在 throw 是一个表达式 <a href="https://wiki.php.net/rfc/throw_expression">RFC</a> 430 </li> 431 <li> 432 允许对象的 ::class <a href="https://wiki.php.net/rfc/class_name_literal_on_object">RFC</a> 433 </li> 434 </ul> 435 436 <h2 class="php8-h2 php8-h2_margin-top">新的类、接口、函数</h2> 437 <ul> 438 <li> 439 <a href="https://wiki.php.net/rfc/weak_maps">Weak Map</a> 类 440 </li> 441 <li> 442 <a href="https://wiki.php.net/rfc/stringable">Stringable</a> 接口 443 </li> 444 <li> 445 <a href="https://wiki.php.net/rfc/str_contains">str_contains()</a>、 446 <a href="https://wiki.php.net/rfc/add_str_starts_with_and_ends_with_functions">str_starts_with()</a>、 447 <a href="https://wiki.php.net/rfc/add_str_starts_with_and_ends_with_functions">str_ends_with()</a> 448 </li> 449 <li> 450 <a href="https://github.com/php/php-src/pull/4769">fdiv()</a> 451 </li> 452 <li> 453 <a href="https://wiki.php.net/rfc/get_debug_type">get_debug_type()</a> 454 </li> 455 <li> 456 <a href="https://github.com/php/php-src/pull/5427">get_resource_id()</a> 457 </li> 458 <li> 459 <a href="https://wiki.php.net/rfc/token_as_object">token_get_all()</a> 对象实现 460 </li> 461 <li> 462 <a href="https://wiki.php.net/rfc/dom_living_standard_api">New DOM Traversal and Manipulation APIs</a> 463 </li> 464 </ul> 465 </div> 466 </div> 467</section> 468 469<section class="php8-section php8-section_dark php8-section_footer php8-footer"> 470 <div class="php8-section__content"> 471 <h2 class="php8-h2 center"> 472 性能更好，语法更好，类型安全更完善 473 </h2> 474 <div class="php8-button-wrapper center"> 475 <a class="php8-button php8-button_light" href="/downloads">更新到 PHP 8！</a> 476 </div> 477 <div class="php8-footer__content"> 478 <p> 479 请访问 <a href="http://www.php.net/downloads">下载</a> 页面下载 PHP 8 源代码。 480 在 <a href="http://windows.php.net/download">PHP for Windows</a> 站点中可找到 Windows 二进制文件。 481 <a href="http://www.php.net/ChangeLog-8.php">ChangeLog</a> 中有变更历史记录清单。 482 </p> 483 <p> 484 PHP 手册中有 <a href="/manual/zh/migration80.php">迁移指南</a>。 485 请参考它描述的新功能详细清单、向后不兼容的变化。 486 </p> 487 </div> 488 </div> 489</section> 490 491 492 493 494<?php site_footer(); 495
