[Threshold]

No, it definitely will not.

You are creating a variable 'id', but you haven't given it a value. Thus giving it a default value of 0, meaning you will just get the error messages/syntax message every time you use the command, regardless of the parameters you enter. Also, you are missing a bracket which would just create more errors within the script.

The correct code for this would be:
With SSCANF include/plugin (RECOMMENDED):

pawn Код:

CMD:dance(playerid, params[])
{
    new selection;
    if(sscanf(params, "d", selection))
    {
        SendClientMessage(playerid, COLOR_WHITE, "USAGE: /dance [ID]");
        SendClientMessage(playerid, COLOR_LIGHTBLUE, "IDs: 1, 2, 3, 4");
        return 1;
    }
    switch(selection)
    {
        case 1: SetPlayerSpecialAction(playerid, SPECIAL_ACTION_DANCE1);
        case 2: SetPlayerSpecialAction(playerid, SPECIAL_ACTION_DANCE2);
        case 3: SetPlayerSpecialAction(playerid, SPECIAL_ACTION_DANCE3);
        case 4: SetPlayerSpecialAction(playerid, SPECIAL_ACTION_DANCE4);
    }
    return 1;
}

Without SSCANF Plugin/Include (NOT RECOMMENDED):

pawn Код:

CMD:dance(playerid, params[])
{
    if(!strlen(params))
    {
        SendClientMessage(playerid, COLOR_WHITE, "USAGE: /dance [ID]");
        SendClientMessage(playerid, COLOR_LIGHTBLUE, "IDs: 1, 2, 3, 4");
        return 1;
    }
    new selection = strval(params);
    switch(selection)
    {
        case 1: SetPlayerSpecialAction(playerid, SPECIAL_ACTION_DANCE1);
        case 2: SetPlayerSpecialAction(playerid, SPECIAL_ACTION_DANCE2);
        case 3: SetPlayerSpecialAction(playerid, SPECIAL_ACTION_DANCE3);
        case 4: SetPlayerSpecialAction(playerid, SPECIAL_ACTION_DANCE4);
        default:
        {
            SendClientMessage(playerid, COLOR_WHITE, "USAGE: /dance [ID]");
            SendClientMessage(playerid, COLOR_LIGHTBLUE, "IDs: 1, 2, 3, 4");
        }
    }
    return 1;
}