1"use strict";(self.webpackChunksample_website=self.webpackChunksample_website||[]).push([[1064],{3905:(e,t,n)=>{n.d(t,{Zo:()=>m,kt:()=>k});var o=n(7294);function a(e,t,n){return t in e?Object.defineProperty(e,t,{value:n,enumerable:!0,configurable:!0,writable:!0}):e[t]=n,e}function i(e,t){var n=Object.keys(e);if(Object.getOwnPropertySymbols){var o=Object.getOwnPropertySymbols(e);t&&(o=o.filter((function(t){return Object.getOwnPropertyDescriptor(e,t).enumerable}))),n.push.apply(n,o)}return n}function r(e){for(var t=1;t<arguments.length;t++){var n=null!=arguments[t]?arguments[t]:{};t%2?i(Object(n),!0).forEach((function(t){a(e,t,n[t])})):Object.getOwnPropertyDescriptors?Object.defineProperties(e,Object.getOwnPropertyDescriptors(n)):i(Object(n)).forEach((function(t){Object.defineProperty(e,t,Object.getOwnPropertyDescriptor(n,t))}))}return e}function l(e,t){if(null==e)return{};var n,o,a=function(e,t){if(null==e)return{};var n,o,a={},i=Object.keys(e);for(o=0;o<i.length;o++)n=i[o],t.indexOf(n)>=0||(a[n]=e[n]);return a}(e,t);if(Object.getOwnPropertySymbols){var i=Object.getOwnPropertySymbols(e);for(o=0;o<i.length;o++)n=i[o],t.indexOf(n)>=0||Object.prototype.propertyIsEnumerable.call(e,n)&&(a[n]=e[n])}return a}var s=o.createContext({}),c=function(e){var t=o.useContext(s),n=t;return e&&(n="function"==typeof e?e(t):r(r({},t),e)),n},m=function(e){var t=c(e.components);return o.createElement(s.Provider,{value:t},e.children)},p="mdxType",d={inlineCode:"code",wrapper:function(e){var t=e.children;return o.createElement(o.Fragment,{},t)}},u=o.forwardRef((function(e,t){var n=e.components,a=e.mdxType,i=e.originalType,s=e.parentName,m=l(e,["components","mdxType","originalType","parentName"]),p=c(n),u=a,k=p["".concat(s,".").concat(u)]||p[u]||d[u]||i;return n?o.createElement(k,r(r({ref:t},m),{},{components:n})):o.createElement(k,r({ref:t},m))}));function k(e,t){var n=arguments,a=t&&t.mdxType;if("string"==typeof e||a){var i=n.length,r=new Array(i);r[0]=u;var l={};for(var s in t)hasOwnProperty.call(t,s)&&(l[s]=t[s]);l.originalType=e,l[p]="string"==typeof e?e:a,r[1]=l;for(var c=2;c<i;c++)r[c]=n[c];return o.createElement.apply(null,r)}return o.createElement.apply(null,n)}u.displayName="MDXCreateElement"},3196:(e,t,n)=>{n.r(t),n.d(t,{assets:()=>s,contentTitle:()=>r,default:()=>d,frontMatter:()=>i,metadata:()=>l,toc:()=>c});var o=n(3117),a=(n(7294),n(3905));const i={title:"Migrating from 3.x to 4.0",sidebar_position:2,slug:"/migrating-from-3-x-to-4-0/"},r=void 0,l={unversionedId:"categories/Migrations/migrating-from-3-to-4",id:"version-3.x/categories/Migrations/migrating-from-3-to-4",title:"Migrating from 3.x to 4.0",description:"The 4.0.0 release adds quite a lot of new features, which are detailed below, but it also contains a few API breaking changes (hence the major bump).",source:"@site/versioned_docs/version-3.x/categories/06-Migrations/migrating-from-3-to-4.md",sourceDirName:"categories/06-Migrations",slug:"/migrating-from-3-x-to-4-0/",permalink:"/docs/v3/migrating-from-3-x-to-4-0/",draft:!1,editUrl:"https://github.com/socketio/socket.io-website/edit/main/versioned_docs/version-3.x/categories/06-Migrations/migrating-from-3-to-4.md",tags:[],version:"3.x",lastUpdatedAt:1784117104,formattedLastUpdatedAt:"Jul 15, 2026",sidebarPosition:2,frontMatter:{title:"Migrating from 3.x to 4.0",sidebar_position:2,slug:"/migrating-from-3-x-to-4-0/"},sidebar:"version-3.x/sidebar",previous:{title:"Migrating from 2.x to 3.0",permalink:"/docs/v3/migrating-from-2-x-to-3-0/"},next:{title:"FAQ",permalink:"/docs/v3/faq/"}},s={},c=[{value:"Breaking changes",id:"breaking-changes",level:3},{value:"<code>io.to()</code> is now immutable",id:"ioto-is-now-immutable",level:4},{value:"<code>wsEngine</code> option",id:"wsengine-option",level:4},{value:"Configuration",id:"configuration",level:3},{value:"Ensure compatibility with Swift v15 clients",id:"ensure-compatibility-with-swift-v15-clients",level:4},{value:"The default value of <code>pingTimeout</code> was increased",id:"the-default-value-of-pingtimeout-was-increased",level:4},{value:"New features",id:"new-features",level:3},{value:"Allow excluding specific rooms when broadcasting",id:"allow-excluding-specific-rooms-when-broadcasting",level:4},{value:"Allow to pass an array to <code>io.to()</code>
1",id:"allow-to-pass-an-array-to-ioto",level:4},{value:"Additional utility methods",id:"additional-utility-methods",level:4},{value:"Typed events",id:"typed-events",level:4},{value:"<code>autoUnref</code> option",id:"autounref-option",level:4},{value:"Known migration issues",id:"known-migration-issues",level:3}],m={toc:c},p="wrapper";function d(e){let{components:t,...i}=e;return(0,a.kt)(p,(0,o.Z)({},m,i,{components:t,mdxType:"MDXLayout"}),(0,a.kt)("p",null,"The 4.0.0 release adds quite a lot of new features, which are detailed ",(0,a.kt)("a",{parentName:"p",href:"#New-features"},"below"),", but it also contains a few API breaking changes (hence the major bump)."),(0,a.kt)("p",null,"Please note that these breaking changes only impact the API on the server side. The Socket.IO protocol itself was not updated, so a v3 client ",(0,a.kt)("strong",{parentName:"p"},"will")," be able to reach a v4 server and vice-versa. Besides, the compatibility mode (",(0,a.kt)("a",{parentName:"p",href:"/docs/v3/server-initialization/#allowEIO3"},(0,a.kt)("inlineCode",{parentName:"a"},"allowEIO3: true")),") is still available between a Socket.IO v2 client and a Socket.IO v4 server."),(0,a.kt)("p",null,"Here is the complete list of changes:"),(0,a.kt)("ul",null,(0,a.kt)("li",{parentName:"ul"},(0,a.kt)("a",{parentName:"li",href:"#Breaking-changes"},"Breaking changes"),(0,a.kt)("ul",{parentName:"li"},(0,a.kt)("li",{parentName:"ul"},(0,a.kt)("a",{parentName:"li",href:"#io-to-is-now-immutable"},(0,a.kt)("inlineCode",{parentName:"a"},"io.to()")," is now immutable")),(0,a.kt)("li",{parentName:"ul"},(0,a.kt)("a",{parentName:"li",href:"#wsEngine-option"},(0,a.kt)("inlineCode",{parentName:"a"},"wsEngine")," option")))),(0,a.kt)("li",{parentName:"ul"},(0,a.kt)("a",{parentName:"li",href:"#Configuration"},"Configuration"),(0,a.kt)("ul",{parentName:"li"},(0,a.kt)("li",{parentName:"ul"},(0,a.kt)("a",{parentName:"li",href:"#Ensure-compatibility-with-Swift-v15-clients"},"Ensure compatibility with Swift v15 clients")),(0,a.kt)("li",{parentName:"ul"},(0,a.kt)("a",{parentName:"li",href:"#The-default-value-of-pingTimeout-was-increased"},"The default value of ",(0,a.kt)("inlineCode",{parentName:"a"},"pingTimeout")," was increased")))),(0,a.kt)("li",{parentName:"ul"},(0,a.kt)("a",{parentName:"li",href:"#New-features"},"New features"),(0,a.kt)("ul",{parentName:"li"},(0,a.kt)("li",{parentName:"ul"},(0,a.kt)("a",{parentName:"li",href:"#Allow-excluding-specific-rooms-when-broadcasting"},"Allow excluding specific rooms when broadcasting")),(0,a.kt)("li",{parentName:"ul"},(0,a.kt)("a",{parentName:"li",href:"#Allow-to-pass-an-array-to-io-to"},"Allow to pass an array to ",(0,a.kt)("inlineCode",{parentName:"a"},"io.to()"))),(0,a.kt)("li",{parentName:"ul"},(0,a.kt)("a",{parentName:"li",href:"#Additional-utility-methods"},"Additional utility methods")),(0,a.kt)("li",{parentName:"ul"},(0,a.kt)("a",{parentName:"li",href:"#Typed-events"},"Typed events")),(0,a.kt)("li",{parentName:"ul"},(0,a.kt)("a",{parentName:"li",href:"#autoUnref-option"},(0,a.kt)("inlineCode",{parentName:"a"},"autoUnref")," option")))),(0,a.kt)("li",{parentName:"ul"},(0,a.kt)("a",{parentName:"li",href:"#Known-migration-issues"},"Known migration issues"))),(0,a.kt)("h3",{id:"breaking-changes"},"Breaking changes"),(0,a.kt)("h4",{id:"ioto-is-now-immutable"},(0,a.kt)("inlineCode",{parentName:"h4"},"io.to()")," is now immutable"),(0,a.kt)("p",null,"Previously, broadcasting to a given room (by calling ",(0,a.kt)("inlineCode",{parentName:"p"},"io.to()"),") would mutate the io instance, which could lead to surprising behaviors, like:"),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-js"},'io.to("room1");\nio.to("room2").emit(/* ... */); // also sent to room1\n\n// or with async/await\nio.to("room3").emit("details", await fetchDetails()); // random behavior: maybe in room3, maybe to all clients\n')),(0,a.kt)("p",null,"Calling ",(0,a.kt)("inlineCode",{parentName:"p"},"io.to()")," (or any other broadcast modifier) will now return an immutable instance."),(0,a.kt)("p",null,"Examples:"),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-js"},'const operator1 = io.to("room1");\nconst operator2 = operator1.to("room2");\nconst operator3 = socket.broadcast;\nconst operator4 = socket.to("room3").to("room4");\n\noperator1.emit(/* ... */); // only to clients in "room1"\noperator2.emit(/* ... */); // to clients in "room1" or in "room2"\noperator3.emit(/* ... */); // to all clients but the sender\noperator4.emit(/* ... */); // to clients in "room3" or in "room4" but the sender\n')),(0,a.kt)("h4",{id:"wsengine-option"},(0,a.kt)("inlineCode",{parentName:"h4"},"wsEngine")," option"),(0,a.kt)("p",null,"The format of the ",(0,a.kt)("a",{parentName:"p",href:"/docs/v3/server-initialization/#wsEngine"},(0,a.kt)("inlineCode",{parentName:"a"},"wsEngine"))," option was updated in order to get rid of the following error:"),(0,a.kt)("p",null,(0,a.kt)("inlineCode",{parentName:"p"},"Critical dependency: the request of a dependency is an expression")),(0,a.kt)("p",null,"when bundling the server with webpack."),(0,a.kt)("p",null,"Before:"),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-js"},'const io = require("socket.io")(httpServer, {\n wsEngine: "eiows"\n});\n')),(0,a.kt)("p",null,"After:"),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-js"},'const io = require("socket.io")(httpServer, {\n wsEngine: require("eiows").Server\n});\n')),(0,a.kt)("h3",{id:"configuration"},"Configuration"),(0,a.kt)("h4",{id:"ensure-compatibility-with-swift-v15-clients"},"Ensure compatibility with Swift v15 clients"),(0,a.kt)("p",null,"Before version 16.0.0, the Swift client would not include the ",(0,a.kt)("inlineCode",{parentName:"p"},"EIO")," query parameter in the HTTP requests, and the Socket.IO v3 server would infer ",(0,a.kt)("inlineCode",{parentName:"p"},"EIO=4")," by default."),(0,a.kt)("p",null,"That's why a Swift client v15 was not able to connect to the server, even when the compatibility mode was enabled (",(0,a.kt)("a",{parentName:"p",href:"/docs/v3/server-initialization/#allowEIO3"},(0,a.kt)("inlineCode",{parentName:"a"},"allowEIO3: true")),"), unless you explicitly specified the query param:"),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-swift"},'let manager = SocketManager(socketURL: URL(string: "http://localhost:8080")!, config: [\n .log(true),\n .connectParam
1s(["EIO": "3"])\n])\nlet socket = manager.defaultSocket\n')),(0,a.kt)("p",null,"The Socket.IO v4 server will now infer ",(0,a.kt)("inlineCode",{parentName:"p"},"EIO=3")," if the ",(0,a.kt)("inlineCode",{parentName:"p"},"EIO")," query param is not included."),(0,a.kt)("h4",{id:"the-default-value-of-pingtimeout-was-increased"},"The default value of ",(0,a.kt)("inlineCode",{parentName:"h4"},"pingTimeout")," was increased"),(0,a.kt)("p",null,"The default value of ",(0,a.kt)("a",{parentName:"p",href:"/docs/v3/server-initialization/#pingTimeout"},(0,a.kt)("inlineCode",{parentName:"a"},"pingTimeout"))," (used in the ",(0,a.kt)("a",{parentName:"p",href:"/docs/v3/how-it-works/#Disconnection-detection"},"heartbeat mechanism"),") value was updated from 60000 to 5000 in ",(0,a.kt)("inlineCode",{parentName:"p"},"[email protected]")," (March 2018)."),(0,a.kt)("p",null,"The reasoning back then:"),(0,a.kt)("p",null,'Some users experienced long delays between disconnection on the server-side and on the client-side. The "disconnect" event would take a long time to fire in the browser, probably due to a timer being delayed. Hence the change.'),(0,a.kt)("p",null,"That being said, the current value (5s) caused unexpected disconnections when a big payload was sent over a slow network, because it prevents the ping-pong packets from being exchanged between the client and the server. This can also happen when a synchronous task blocks the server for more than 5 seconds."),(0,a.kt)("p",null,"The new value (20s) thus seems like a good balance between quick disconnection detection and tolerance to various delays."),(0,a.kt)("h3",{id:"new-features"},"New features"),(0,a.kt)("h4",{id:"allow-excluding-specific-rooms-when-broadcasting"},"Allow excluding specific rooms when broadcasting"),(0,a.kt)("p",null,"Thanks to the awesome work of ",(0,a.kt)("a",{parentName:"p",href:"https://github.com/sebamarynissen"},"Sebastiaan Marynissen"),", you can now exclude a specific room when broadcasting:"),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-js"},'io.except("room1").emit(/* ... */); // to all clients except the ones in "room1"\nio.to("room2").except("room3").emit(/* ... */); // to all clients in "room2" except the ones in "room3"\n\nsocket.broadcast.except("room1").emit(/* ... */); // to all clients except the ones in "room1" and the sender\nsocket.except("room1").emit(/* ... */); // same as above\nsocket.to("room4").except("room5").emit(/* ... */); // to all clients in "room4" except the ones in "room5" and the sender\n')),(0,a.kt)("h4",{id:"allow-to-pass-an-array-to-ioto"},"Allow to pass an array to ",(0,a.kt)("inlineCode",{parentName:"h4"},"io.to()")),(0,a.kt)("p",null,"The ",(0,a.kt)("inlineCode",{parentName:"p"},"to()")," method now accepts an array of rooms."),(0,a.kt)("p",null,"Before:"),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-js"},'const rooms = ["room1", "room2", "room3"];\nfor (const room of rooms) {\n io.to(room);\n}\n// broadcast to clients in "room1", "room2" or "room3"\n// WARNING !!! this does not work anymore in v4, see the breaking change above\nio.emit(/* ... */);\n')),(0,a.kt)("p",null,"After:"),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-js"},'io.to(["room1", "room2", "room3"]).emit(/* ... */);\n\nsocket.to(["room1", "room2", "room3"]).emit(/* ... */);\n')),(0,a.kt)("h4",{id:"additional-utility-methods"},"Additional utility methods"),(0,a.kt)("p",null,"Some (long-awaited) methods were added:"),(0,a.kt)("ul",null,(0,a.kt)("li",{parentName:"ul"},(0,a.kt)("inlineCode",{parentName:"li"},"socketsJoin"),": makes the matching socket instances join the specified rooms")),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-js"},'// make all Socket instances join the "room1" room\nio.socketsJoin("room1");\n\n// make all Socket instances of the "admin" namespace in the "room1" room join the "room2" room\nio.of("/admin").in("room1").socketsJoin("room2");\n')),(0,a.kt)("ul",null,(0,a.kt)("li",{parentName:"ul"},(0,a.kt)("inlineCode",{parentName:"li"},"socketsLeave"),": makes the matching socket instances leave the specified rooms")),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-js"},'// make all Socket instances leave the "room1" room\nio.socketsLeave("room1");\n\n// make all Socket instances of the "admin" namespace in the "room1" room leave the "room2" room\nio.of("/admin").in("room1").socketsLeave("room2");\n')),(0,a.kt)("ul",null,(0,a.kt)("li",{parentName:"ul"},(0,a.kt)("inlineCode",{parentName:"li"},"disconnectSockets"),": makes the matching socket instances disconnect")),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-js"},'// make all Socket instances disconnect\nio.disconnectSockets();\n\n// make all Socket instances of the "admin" namespace in the "room1" room disconnect\nio.of("/admin").in("room1").disconnectSockets();\n\n// this also works with a single socket ID\nio.of("/admin").in(theSocketId).disconnectSockets();\n')),(0,a.kt)("ul",null,(0,a.kt)("li",{parentName:"ul"},(0,a.kt)("inlineCode",{parentName:"li"},"fetchSockets"),": returns the matching socket instances")),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-js"},'// return all Socket instances\nconst sockets = await io.fetchSockets();\n\n// return all Socket instances of the "admin" namespace in the "room1" room\nconst sockets = await io.of("/admin").in("room1").fetchSockets();\n\n// this also works with a single socket ID\nconst sockets = await io.in(theSocketId).fetchSockets();\n')),(0,a.kt)("p",null,"The ",(0,a.kt)("inlineCode",{parentName:"p"},"sockets")," variable in the example above is an array of objects exposing a subset of the usual Socket class:"),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-js"},"for (const socket of sockets) {\n console.log(socket.id);\n console.log(socket.handshake);\n console.log(socket.rooms);\n socket.emit(/* ... */);\n socket.join(/* ... */);\n socket.leave(/* ... */);\n socket.disconnect(/* ... */);\n}\n")),(0,a.kt)("p",null,"Those methods share the same semantics as broadcasting, and the same filters apply:"),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-js"},'io.of("/admin").in("room1").except("room2").local.disconnectSockets();\n')),(0,a.kt)("p",null,'Which makes all Socket instances of the "admin" namespace'),(0,a.kt)("ul",null,(0,a.kt)("li",{parentName:"ul"},'in the "room1" room (',(0,a.kt)("inlineCode",{parentName:"li"},'in("room1")')," or ",(0,a.kt)("inlineCode",{parentName:"li"},'to("room1")'),")"),(0,a.kt)("li",{parentName:"ul"},'except the ones in "room2" (',(0,a.kt)("inlineCode",{parentName:"li"},'except("room2")'),")"),(0,a.kt)("li",{parentName:"ul"},"and only on the current Socket.IO server (",(0,a.kt)("inlineCode",{parentName:"li"},"local"),")")),(0,a.kt)("p",null,"disconnect."),(0,a.kt)("h4",{id:"typed-events"},"Typed events"),(0,a.kt)("p",null,"Thanks to the awesome work of ",(0,a.kt)("a",{parentName:"p",href:"https://github.com/MaximeKjaer"},"Maxime Kjaer"),", TypeScript users can now type the events sent between the client and the server."),(0,a.kt)("p",null,"First, you declare the signature of each event:"),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-ts"},"interface ClientToServerEvents {\n noArg: () => void;\n basicEmit: (a: number, b: string, c: number[]) => void;\n}\n\ninterface ServerToClientEvents {\n withAck: (d: string, cb: (e: number) => void) => void;\n}\n")),(0,a.kt)("p",null,"And you can now use them on the client side:"),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-ts"},'import { io, Socket } from "socket.io-client";\n\nconst socket: Socket<ServerToClientEvents, ClientToServerEvents> = io();\n\nsocket.emit("noArg");\n\nsocket.emit("basicEmit", 1, "2", [3]);\n\nsocket.on("withAck", (d, cb) => {\n cb(4);\n});\n')),(0,a.kt)("p",null,"Your IDE should now properly infer the type of each argument:"),(0,a.kt)("p",null,(0,a.kt)("img",{alt:"Typed events",src:n(6738).Z,width:"539",height:"180"})),(0,a.kt)("p",null,"Similarly on the server side (the ",(0,a.kt)("inlineCode",{parentName:"p"},"ServerToClientEvents")," and ",(0,a.kt)("inlineCode",{parentName:"p"},"ClientToServerEvents")," are reversed):"),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-ts"},'import { Server } from "socket.io";\n\nconst io = new Server<ClientToServerEvents, ServerToClientEvents>(3000);\n\nio.on("connection", (socket) => {\n socket.on("noArg", () => {\n // ...\n });\n\n socket.on("basicEmit", (a, b, c) => {\n // ...\n });\n\n socket.emit("withAck", "42", (e) => {\n console.log(e);\n });\n});\n')),(0,a.kt)("p",null,"By default, the events are untyped and the arguments will be inferred as ",(0,a.kt)("inlineCode",{parentName:"p"},"any"),"."),(0,a.kt)("h4",{id:"autounref-option"},(0,a.kt)("inlineCode",{parentName:"h4"},"autoUnref")," option"),(0,a.kt)("p",null,"And finally, thanks to the awesome work of ",(0,a.kt)("a",{parentName:"p",href:"https://github.com/KCErb"},"KC Erb"),", the ",(0,a.kt)("inlineCode",{parentName:"p"},"autoUnref")," option was added."),(0,a.kt)("p",null,"With ",(0,a.kt)("inlineCode",{parentName:"p"},"autoUnref")," set to true (default: false), the Socket.IO client will allow the program to exit if there is no other active timer/socket in the event system:"),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-js"},"const socket = io({\n autoUnref: true\n});\n")),(0,a.kt)("p",null,"Note: this option only applies to Node.js clients."),(0,a.kt)("h3",{id:"known-migration-issues"},"Known migration issues"),(0,a.kt)("ul",null,(0,a.kt)("li",{parentName:"ul"},(0,a.kt)("inlineCode",{parentName:"li"},"cannot get emit of undefined"))),(0,a.kt)("p",null,"The following expression:"),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-js"}
1,'socket.to("room1").broadcast.emit(/* ... */);\n')),(0,a.kt)("p",null,"was working in Socket.IO v3 but is now considered invalid, as the ",(0,a.kt)("inlineCode",{parentName:"p"},"broadcast")," flag is useless because the ",(0,a.kt)("inlineCode",{parentName:"p"},'to("room1")')," method already puts the Socket instance in broadcasting mode."),(0,a.kt)("pre",null,(0,a.kt)("code",{parentName:"pre",className:"language-js"},'// VALID\nsocket.broadcast.emit(/* ... */); // to all clients but the sender\nsocket.to("room1").emit(/* ... */); // to clients in "room1" but the sender\n\n// VALID (but useless \'broadcast\' flag)\nsocket.broadcast.to("room1").emit(/* ... */);\n\n// INVALID\nsocket.to("room1").broadcast.emit(/* ... */);\n')))}d.isMDXComponent=!0},6738:(e,t,n)=>{n.d(t,{Z:()=>o});const o=n.p+"assets/images/typed-events-b34a38f7ee1735a61d3135f83518a012.png"}}]);
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