Passing String Variables Using Globals

Can anyone tell me if you can pass string variables using global variables? I know you can pass other variables, such as integer, doubles and boolean, and not have to add anything extra, but whenever I try to pass a string all I get is a bunch of 0's.

Any ideas?

Thanks.

It appears not.....even if you try and create it manually in the platform it will not accept alpha characters.

I guess the next best would be to either write to file, or if it's a really short string, you could convert and store each letter according to its ascii code.

Actually, what I was trying to do was create a string of numbers (both integers and doubles) separated by spaces, then pass that on as a global, and convert it back into the respective numbers once it reaches it's destination.

I'm thinking now maybe, since there are only four or five numbers, I could setup a for statement and assign a variable to each value and pass them on sequentially through a global. Or, if nothing else, create a separate global for each one individually, although I'm not sure I want to do that? I'm liable to have six or seven charts open, or more, with four or five globals assigned to each, and it might get a bit confusing.

Or, maybe I could create a string beginning with the number "1," and add all the other variables, at least the first four, which should be only one digit, so it looks like an actual whole number. Then I could convert that into an integer and pass it as a global, and reverse the process on the other end. I think I might try this first ...


Hey, thanks.

Hi there,

I would just go the Global Variable(Gvar) route......you can have something like 10 000 Gvars, so if you can keep track of the different instances of the EA, there should be no issue storing as many variables as you like.

I typically use a routine that assigns a unique MagicNumber to each instance of an EA, based on currency pair, time frame, EA identifier and unique EA instance ID. You could use a similar structure so that each chart(EA instance) can keep track of its own Gvars via its own MagicNumber. SO by way of example :-

EA 1 EURGBP MagicNumber = 15645 >>>Gvar name = string 15645_var1, 15645_var2,15645_var3,........
EA 1 EURUSD MagicNumber = 10222 >>>Gvar name = string 10222 _var1, 10222 _var2,10222 _var3,........

I actually got it to work in the second instance I referred to above and it works fine. However, it doesn't address the real issue which I briefly referred to here. I was trying to communicate back and forth between two separate accounts using this "TradeSwitch" DLL ... which, the way the code was written, was only setup to communicate one way. So, I thought if I modified the EA's (provided) to seek for globals on the specific account that's transmitting (and received on the other account), instead of sending information via a specific Symbol(), then I could eliminate any possible crosstalk, as both accounts are transmitting and receiving.

Like I said, when communicating only one way, it works great. But, as soon as I hook up the second account to receive, I'm dead in the water.

Yes, this is what's neat about globals, as it allows to create variables "on the fly," so to speak.

why don't you explore using dll's and just letting it handle all the cross-talk and global variables etc instead of trying to shoehorn it into mt4?

Sure, provided of course that you know what you're doing. Also, since I'm using more than one instance of the EA I'm applying this to (currently nine, on each account), I figured it would be easiest for each EA to create a global specific to the chart, and create a single EA that scans for globals and interfaces with the DLL, to transmit the information over to the other account, and vice versa. I think that's pretty straight forward enough.

Although, actually if I could find a way to send the information from each EA (each instance) directly to the DLL without using globals, it might be simpler. In fact I first tried something like this, but couldn't get it to work. I probably should go back and check again.