Run this EA on the EURUSD (for example) Daily:
You'll see like this picture
See also https://docs.mql4.com/cn/check/UninitializeReason
//+------------------------------------------------------------------+ //| Run_And_Compile_EA.mq4 | //| Copyright © 2007, MetaQuotes Software Corp. | //| https://www.metaquotes.net/ru/ | //+------------------------------------------------------------------+ #property copyright "Copyright © 2007, MetaQuotes Software Corp." #property link "https://www.metaquotes.net/ru/" //---- input parameters extern int ExtParam1=1; extern double ExtParam2=25.0; //+------------------------------------------------------------------+ //| expert start function | //+------------------------------------------------------------------+ int start() { //---- Print("ExtParam1=",ExtParam1," ExtParam2=",ExtParam2); //---- return(0); } //+------------------------------------------------------------------+then modify values of inputs and compile EA as shown
You'll see like this picture
See also https://docs.mql4.com/cn/check/UninitializeReason
Dear Mr. Rosh
I understood,I can change some parameters when ea is running
and the ea can run with the new parmetres.
So clever MT4 it is !
Dear Mr. Rosh
Now I can operate a multi Symbol() ea
I have a question:
If the ea is operating,I change some parameters and compile it
What happen ?
Can the ea run with new parameters I do not remove the ea and rebuild it ?