--- title: Generator slug: Web/JavaScript/Reference/Global_Objects/Generator translation_of: Web/JavaScript/Reference/Global_Objects/Generator --- <div>{{JSRef}}</div> <p>O objeto <code><strong>Generator</strong></code> é retornado por {{jsxref("Statements/function*", "generator function", "", 1)}} e conforme <a href="/en-US/docs/Web/JavaScript/Reference/Iteration_protocols#iterable">iterable protocol</a> e o <a href="/en-US/docs/Web/JavaScript/Reference/Iteration_protocols#iterator">iterator protocol</a>.</p> <h2 id="Síntaxe">Síntaxe</h2> <pre class="syntaxbox">function* gen() { yield 1; yield 2; yield 3; } var g = gen(); // "Generator { }"</pre> <h2 id="Métodos">Métodos</h2> <dl> <dt>{{jsxref("Generator.prototype.next()")}}</dt> <dd>Retorna o valor fornecido pela expressão {{jsxref("Operators/yield", "yield")}}.</dd> <dt>{{jsxref("Generator.prototype.return()")}}</dt> <dd>Retorna o valor fornecido a finaliza o generator.</dd> <dt>{{jsxref("Generator.prototype.throw()")}}</dt> <dd>Lança um erro no generator.</dd> </dl> <h2 id="Example">Example</h2> <h3 id="An_infinite_iterator">An infinite iterator</h3> <pre class="brush: js">function* idMaker(){ var index = 0; while(true) yield index++; } var gen = idMaker(); // "Generator { }" console.log(gen.next().value); // 0 console.log(gen.next().value); // 1 console.log(gen.next().value); // 2 // ...</pre> <h2 id="Objeto_legacy_generator">Objeto legacy generator</h2> <p>Firefox (SpiderMonkey) também implementa a versão anterior do generator em <a href="/en-US/docs/Web/JavaScript/New_in_JavaScript/1.7">JavaScript 1.7</a>, onde o asterisco (*) na declaração da função não era necessário (somente era necessário usar a palavra reservada <code>yield</code> no corpo da função). Contudo, legacy generators estão obsoletos. Não os use, eles serão removidos ({{bug(1083482)}}).</p> <h3 id="Métodos_legacy_generator">Métodos legacy generator</h3> <dl> <dt><code>Generator.prototype.next() </code>{{non-standard_inline}}</dt> <dd>Retorna o valor fornecido pela expressão {{jsxref("Operators/yield", "yield")}}. Isto corresponde ao <code>next() </code>do ES6.</dd> <dt><code>Generator.prototype.close()</code> {{non-standard_inline}}</dt> <dd>Fecha o generator, então quando chamar <code>next()</code> um erro {{jsxref("StopIteration")}} será lançado. Isto corresponde ao método <code>return()</code> do ES6.</dd> <dt><code>Generator.prototype.send()</code> {{non-standard_inline}}</dt> <dd>Usado para enviar um valor para o generator. Este valor é retordo pela expressão {{jsxref("Operators/yield", "yield")}}, e retorna o valor fornecido pelo pelo next {{jsxref("Operators/yield", "yield")}}. <code>send(x)</code> corresponde ao <code>next(x)</code> do ES6.</dd> <dt><strong><code>Generator.</code></strong><code>prototype.</code><strong><code>throw()</code> </strong> {{non-standard_inline}}</dt> <dd>Lança um erro no generator. Isto corresponde ao método <code>throw() do ES6.</code></dd> </dl> <h3 id="Exemplo_do_Legacy_generator">Exemplo do Legacy generator</h3> <pre class="brush: js">function* fibonacci() { var a = yield 1; yield a * 2; } var it = fibonacci(); console.log(it); // "Generator { }" console.log(it.next()); // 1 console.log(it.send(10)); // 20 console.log(it.close()); // undefined console.log(it.next()); // throws StopIteration (Como o generator está fechado) </pre> <h2 id="Especificações">Especificações</h2> <table class="standard-table"> <tbody> <tr> <th scope="col">Especificações</th> <th scope="col">Status</th> <th scope="col">Comentário</th> </tr> <tr> <td>{{SpecName('ES6', '#sec-generator-objects', 'Generator objects')}}</td> <td>{{Spec2('ES6')}}</td> <td>Definição Inicial</td> </tr> <tr> <td>{{SpecName('ESDraft', '#sec-generator-objects', 'Generator objects')}}</td> <td>{{Spec2('ESDraft')}}</td> <td> </td> </tr> </tbody> </table> <h2 id="Browser_compatibility">Compatibilidade com navegadores</h2> <p>{{CompatibilityTable}}</p> <div id="compat-desktop"> <table class="compat-table"> <tbody> <tr> <th>Feature</th> <th>Chrome</th> <th>Firefox (Gecko)</th> <th>Internet Explorer</th> <th>Opera</th> <th>Safari</th> </tr> <tr> <td>Basic support</td> <td>{{CompatChrome(39.0)}}</td> <td>{{CompatVersionUnknown}}</td> <td>{{CompatNo}}</td> <td>{{CompatNo}}</td> <td>{{CompatNo}}</td> </tr> </tbody> </table> </div> <div id="compat-mobile"> <table class="compat-table"> <tbody> <tr> <th>Feature</th> <th>Android</th> <th>Android Webview</th> <th>Firefox Mobile (Gecko)</th> <th>IE Mobile</th> <th>Opera Mobile</th> <th>Safari Mobile</th> <th>Chrome for Android</th> </tr> <tr> <td>Basic support</td> <td>{{CompatNo}}</td> <td>{{CompatChrome(39.0)}}</td> <td>{{CompatVersionUnknown}}</td> <td>{{CompatNo}}</td> <td>{{CompatNo}}</td> <td>{{CompatNo}}</td> <td>{{CompatChrome(39.0)}}</td> </tr> </tbody> </table> </div> <h2 id="Veja_Também">Veja Também</h2> <h3 id="Legacy_generators">Legacy generators</h3> <ul> <li>{{jsxref("Statements/Legacy_generator_function", "The legacy generator function", "", 1)}}</li> <li>{{jsxref("Operators/Legacy_generator_function", "The legacy generator function expression", "", 1)}}</li> <li>{{jsxref("StopIteration")}}</li> <li><a href="/en-US/docs/Web/JavaScript/Reference/Deprecated_and_obsolete_features/The_legacy_Iterator_protocol">The legacy Iterator protocol</a></li> </ul> <h3 id="ES6_generators">ES6 generators</h3> <ul> <li>{{jsxref("Functions", "Functions", "", 1)}}</li> <li>{{jsxref("Statements/function", "function")}}</li> <li>{{jsxref("Operators/function", "function expression")}}</li> <li>{{jsxref("Function")}}</li> <li>{{jsxref("Statements/function*", "function*")}}</li> <li>{{jsxref("Operators/function*", "function* expression")}}</li> <li>{{jsxref("GeneratorFunction")}}</li> <li><a href="/en-US/docs/Web/JavaScript/Guide/The_Iterator_protocol">The Iterator protocol</a></li> </ul>