socketio array.splice dont work if make console.log - socket.io

Question

Strange phenomenon. socketio
SERVER
i have that code...
socket.on('disconnect', function(){
console.log('user disconnected');
for(var i=0; i<stores.length; i++ ){
var c = stores[i];
if(c.socketid == socket.id){
stores.splice(i,1);
break;
}
}
});
everything goes well with the .splice. If i print the stores array from elsewhere, it displayed correct ...but in this situation
socket.on('disconnect', function(){
console.log('user disconnected');
for(var i=0; i<stores.length; i++ ){
var c = stores[i];
if(c.socketid == socket.id){
for(var i=0; i<stores.length;i++){
console.log(i+" one"+stores[i].name+"-"+stores[i].id)
}
stores.splice(i,1);
for(var i=0; i<stores.length;i++){
console.log(i+" two"+stores[i].name+"-"+stores[i].id)
}
break;
}
}
});
the array has not lost its values, i visit the page from my browser(i connected),
socket.on('storelogged', function (msg){
var storeInfo = new Object();
storeInfo.name = msg.name;
storeInfo.id = msg.id;
storeInfo.socketid = socket.id;
stores.push(storeInfo);
console.log(msg.name + " has connected with " + msg.id + " id." );
});
so, stores pushed. But when i disconnected in the second situation of socket.on('disconnect',callback) the stores array still contains the values( in other words, splice dont work )
comment for giving, much and better information. Also you can test it and see the results

Answer 1

Your embedded for loops are overwriting the i variable from the top level for loop.
Either use let instead of var as in for (let i = 0; ....) for all your for loops so each has a different locally scoped value of i and the inner loops won't overwrite the outer loops or use a different variable name for the embedded for loops or use .forEach() which creates a new variable for the index.
In addition, after you call .splice() on the array you are iterating, you have decrement the current array index from your for loop or you will skip looking at one of the values in the array because the .splice() moved it down into the index spot that you just removed and that your for loop has already iterated.
For example, you can change variable names of the inner for loops like this:
socket.on('disconnect', function () {
console.log('user disconnected');
for (var i = 0; i < stores.length; i++) {
var c = stores[i];
if (c.socketid == socket.id) {
for (var j = 0; j < stores.length; j++) {
console.log(j + " one" + stores[j].name + "-" + stores[j].id)
}
stores.splice(i, 1);
// make sure not to skip the value we just moved into the i slot in the array
i--;
for (var k = 0; i < stores.length; k++) {
console.log(k + " two" + stores[k].name + "-" + stores[k].id)
}
break;
}
}
});
Or, you can use let for the for loops:
socket.on('disconnect', function () {
console.log('user disconnected');
for (var i = 0; i < stores.length; i++) {
var c = stores[i];
if (c.socketid == socket.id) {
for (let i = 0; i < stores.length; i++) {
console.log(i + " one" + stores[i].name + "-" + stores[i].id)
}
stores.splice(i, 1);
// make sure not to skip the value we just moved into the i slot in the array
i--;
for (let i = 0; i < stores.length; i++) {
console.log(i + " two" + stores[i].name + "-" + stores[i].id)
}
break;
}
}
});
Or, you can use .forEach():
socket.on('disconnect', function () {
console.log('user disconnected');
for (var i = 0; i < stores.length; i++) {
var c = stores[i];
if (c.socketid == socket.id) {
stores.forEach(function(item, index) {
console.log(index + " one" + item.name + "-" + item.id)
});
stores.splice(i, 1);
// make sure not to skip the value we just moved into the i slot in the array
i--;
stores.forEach(function(item, index) {
console.log(index + " one" + item.name + "-" + item.id)
});
break;
}
}
});