这是我的列表（针对 1.0 更新）：

// sending to sender-client only
socket.emit('message', "this is a test");
// sending to all clients, include sender
io.emit('message', "this is a test");
// sending to all clients except sender
socket.broadcast.emit('message', "this is a test");
// sending to all clients in 'game' room(channel) except sender
socket.broadcast.to('game').emit('message', 'nice game');
// sending to all clients in 'game' room(channel), include sender
io.in('game').emit('message', 'cool game');
// sending to sender client, only if they are in 'game' room(channel)
socket.to('game').emit('message', 'enjoy the game');
// sending to all clients in namespace 'myNamespace', include sender
io.of('myNamespace').emit('message', 'gg');
// sending to individual socketid
socket.broadcast.to(socketid).emit('message', 'for your eyes only');
// list socketid
for (var socketid in io.sockets.sockets) {}
 OR
Object.keys(io.sockets.sockets).forEach((socketid) => {});

从@LearnRPG答案中，但使用 1.0：

 // send to current request socket client
 socket.emit('message', "this is a test");
 // sending to all clients, include sender
 io.sockets.emit('message', "this is a test"); //still works
 //or
 io.emit('message', 'this is a test');
 // sending to all clients except sender
 socket.broadcast.emit('message', "this is a test");
 // sending to all clients in 'game' room(channel) except sender
 socket.broadcast.to('game').emit('message', 'nice game');
 // sending to all clients in 'game' room(channel), include sender
 // docs says "simply use to or in when broadcasting or emitting"
 io.in('game').emit('message', 'cool game');
 // sending to individual socketid, socketid is like a room
 socket.broadcast.to(socketid).emit('message', 'for your eyes only');

为了回答@Crashalot评论，socketid来自：

var io = require('socket.io')(server);
io.on('connection', function(socket) { console.log(socket.id); })

以下是关于从 0.9.x 到 1.x 的变化的更完整的答案。

 // send to current request socket client
 socket.emit('message', "this is a test");// Hasn't changed
 // sending to all clients, include sender
 io.sockets.emit('message', "this is a test"); // Old way, still compatible
 io.emit('message', 'this is a test');// New way, works only in 1.x
 // sending to all clients except sender
 socket.broadcast.emit('message', "this is a test");// Hasn't changed
 // sending to all clients in 'game' room(channel) except sender
 socket.broadcast.to('game').emit('message', 'nice game');// Hasn't changed
 // sending to all clients in 'game' room(channel), include sender
 io.sockets.in('game').emit('message', 'cool game');// Old way, DOES NOT WORK ANYMORE
 io.in('game').emit('message', 'cool game');// New way
 io.to('game').emit('message', 'cool game');// New way, "in" or "to" are the exact same: "And then simply use to or in (they are the same) when broadcasting or emitting:" from http://socket.io/docs/rooms-and-namespaces/
 // sending to individual socketid, socketid is like a room
 io.sockets.socket(socketid).emit('message', 'for your eyes only');// Old way, DOES NOT WORK ANYMORE
 socket.broadcast.to(socketid).emit('message', 'for your eyes only');// New way

我想编辑@soyuka的帖子，但我的编辑被同行评审拒绝了。

发出备忘单

io.on('connect', onConnect);
function onConnect(socket){
  // sending to the client
  socket.emit('hello', 'can you hear me?', 1, 2, 'abc');
  // sending to all clients except sender
  socket.broadcast.emit('broadcast', 'hello friends!');
  // sending to all clients in 'game' room except sender
  socket.to('game').emit('nice game', "let's play a game");
  // sending to all clients in 'game1' and/or in 'game2' room, except sender
  socket.to('game1').to('game2').emit('nice game', "let's play a game (too)");
  // sending to all clients in 'game' room, including sender
  io.in('game').emit('big-announcement', 'the game will start soon');
  // sending to all clients in namespace 'myNamespace', including sender
  io.of('myNamespace').emit('bigger-announcement', 'the tournament will start soon');
  // sending to individual socketid (private message)
  socket.to(<socketid>).emit('hey', 'I just met you');
  // sending with acknowledgement
  socket.emit('question', 'do you think so?', function (answer) {});
  // sending without compression
  socket.compress(false).emit('uncompressed', "that's rough");
  // sending a message that might be dropped if the client is not ready to receive messages
  socket.volatile.emit('maybe', 'do you really need it?');
  // sending to all clients on this node (when using multiple nodes)
  io.local.emit('hi', 'my lovely babies');
};

broadcast.emit 将消息发送到所有其他客户端（发件人除外）

socket.on('cursor', function(data) {
  socket.broadcast.emit('msg', data);
});

对于房间内的命名空间，循环访问房间中的客户端列表（类似于 Nav 的答案）是我发现的仅有的两种可行的方法之一。 另一种是使用排除。 例如

socket.on('message',function(data) {
    io.of( 'namespace' ).in( data.roomID ).except( socket.id ).emit('message',data);
}

V4.x 中服务器端所有有效的发出事件列表

io.on("connection", (socket) => {
// basic emit
socket.emit(/* ... */);
// to all clients in the current namespace except the sender
socket.broadcast.emit(/* ... */);
// to all clients in room1 except the sender
socket.to("room1").emit(/* ... */);
// to all clients in room1 and/or room2 except the sender
socket.to(["room1", "room2"]).emit(/* ... */);
// to all clients in room1
io.in("room1").emit(/* ... */);
// to all clients in room1 and/or room2 except those in room3
io.to(["room1", "room2"]).except("room3").emit(/* ... */);
// to all clients in namespace "myNamespace"
io.of("myNamespace").emit(/* ... */);
// to all clients in room1 in namespace "myNamespace"
io.of("myNamespace").to("room1").emit(/* ... */);
// to individual socketid (private message)
io.to(socketId).emit(/* ... */);
// to all clients on this node (when using multiple nodes)
io.local.emit(/* ... */);
// to all connected clients
io.emit(/* ... */);
// WARNING: `socket.to(socket.id).emit()` will NOT work, as it will send to everyone in the room
// named `socket.id` but the sender. Please use the classic `socket.emit()` instead.
// with acknowledgement
socket.emit("question", (answer) => {
    // ...
});
// without compression
socket.compress(false).emit(/* ... */);
// a message that might be dropped if the low-level transport is not writable
socket.volatile.emit(/* ... */);
});

客户端

// basic emit
    socket.emit(/* ... */);
// with acknowledgement
    socket.emit("question", (answer) => {
        // ...
    });
// without compression
    socket.compress(false).emit(/* ... */);
// a message that might be dropped if the low-level transport is not writable
    socket.volatile.emit(/* ... */);

指向源的存档链接 => http://archive.today/2021.06.22-023900/https://socket.io/docs/v4/emit-cheatsheet/index.html

其他情况

io.of('/chat').on('connection', function (socket) {
    //sending to all clients in 'room' and you
    io.of('/chat').in('room').emit('message', "data");
};

更新了列表以获取更多文档。

socket.emit('message', "this is a test"); //sending to sender-client only
socket.broadcast.emit('message', "this is a test"); //sending to all clients except sender
socket.broadcast.to('game').emit('message', 'nice game'); //sending to all clients in 'game' room(channel) except sender
socket.to('game').emit('message', 'enjoy the game'); //sending to sender client, only if they are in 'game' room(channel)
socket.broadcast.to(socketid).emit('message', 'for your eyes only'); //sending to individual socketid
io.emit('message', "this is a test"); //sending to all clients, include sender
io.in('game').emit('message', 'cool game'); //sending to all clients in 'game' room(channel), include sender
io.of('myNamespace').emit('message', 'gg'); //sending to all clients in namespace 'myNamespace', include sender
socket.emit(); //send to all connected clients
socket.broadcast.emit(); //send to all connected clients except the one that sent the message
socket.on(); //event listener, can be called on client to execute on server
io.sockets.socket(); //for emiting to specific clients
io.sockets.emit(); //send to all connected clients (same as socket.emit)
io.sockets.on() ; //initial connection from a client.

希望这有帮助。

针对 Socket.io v4.0.0+ 进行了更新

若要在 v4 中向除发送方之外的所有客户端发出，请使用：

socket.broadcast.emit(/* ... */);

示例用法

io.on("connection", (socket) => {
   socket.on("message", (message) => {
      //sends "newMessage" to all sockets except sender
      socket.broadcast.emit("newMessage", message)
   })
})

使用此编码

io.sockets.on('connection', function (socket) {
    socket.on('mousemove', function (data) {
        socket.broadcast.emit('moving', data);
    });

这个socket.broadcast.emit（）将在函数中发出除发射的服务器之外的所有东西

我正在使用命名空间和房间 - 我发现

socket.broadcast.to('room1').emit('event', 'hi');

在何处工作

namespace.broadcast.to('room1').emit('event', 'hi');

冇

（如果其他人遇到这个问题）