我正在做一个socket.io，Node项目，我不理解调用函数的顺序。我有以下服务器代码：

//Socket setup
var io = require('socket.io')(http);
var c= [];

//functions
function y(clientid){
    console.log('Show clients: '+c)
}

var x = function(socketid, fn) {
    var customid = y(socketid)
    console.log('x is calling');
    fn(customid);
};


io.on('connection', (socket) => {
    console.log('User connected with %s', socket.id);

    socket.on('storeClientInfo', function (data) {
        console.log('Thought this would be the first call')
        //clients.push here
    });
    
    
    x(socket.id, function(socketid, ) {
        socket.emit('random', {
            test1: 'test1',
            test2: 'test1'
        });

    });
});

我为客户提供的代码是：

var socket = io();

        socket.on('connect', function () {
            socket.emit('storeClientInfo', { customId:Math.floor(Math.random() * 100 + 1 )});
        });

        socket.on('random', function (message) {
              //display message here
        });

我的控制台日志输出：

User connected with MH0WD_zNzVOzi_6oABAB
Show clients: 
x is calling
Thought this would be the first call

现在我的问题是：为什么一开始该方法被称为而不是socket.on（'storeClientInfo'）？

问候