How to store AccountBalance() into a variable? - mql4

Question

if(Total_sell_pos() == 0 && Total_buy_pos() == 0) {
double previous_balance = AccountBalance(); //usd1000
}
if (AccountEquity() > previous_balance + (previous_balance *0.05)){ //usd1000 + 50 = usd1050
CloseSellOrders();
CloseBuyOrders();
Delete_Pendings();
}
if Equity more than usd1050 then delete pending and orders.
But why when run the code, it keep delete pending and orders immediately even when Equity is less than previous balance?
The following code is the problem, and I replace it :
AccountEquity() > previous_balance + (previous_balance *0.05)
with
AccountEquity() > 1050
then only it works. I did try to check the value :
double check_value = previous_balance + (previous_balance *0.05);
printf (check_value); //1050
May I know why I cannot use the following code?
AccountEquity() > previous_balance + (previous_balance *0.05)

Answer 1

Q: How to store AccountBalance() into a variable?
Let's start with the variable - declare it:
double aPreviousBALANCE;
The scope-of-declaration is driven by the enclosing code-block boundaries. MQL4/5 can declare a variable on the "global"-scope, that may become visible from inside other code-blocks, but if any such has a variable name identical to the "global"-scope defined one, the locally declared ( explicitly in the code, or introduced from the function-parameters' declaration in the call-signature specification ) will "shade-off" the access to the variable declared on the "global"-scope. This you have to check in the original code and MQL4/5-IDE may warn you about such collision(s) during the compilation ( ref. Compiler Warning Messages ).
Let's store in it the actual state, we'll have more steps here:
RefreshRates(); // Force a state-update
aPreviousBALANCE = AccountInfoDouble( ACCOUNT_BALANCE ); // Store an updated value
Q: May I know why I cannot use the following code?
Well, any language, MQL4/5 not being an exception, has some order of execution of mathematical operators. MQL4 need not and does not have the warranty about using the same one as any other language we may have had some prior experience. So, always be rather explicit in this a specify all ordering via explicit parentheses, this will save you any further "surprises" when the language parser / compiler will suddenly change the priority of operators and sudden nightmares will appear. Not worth a single such shock to ever happen:
if ( ( ( a * b ) + c ) < fun() ) // is EXPLICIT and a way safer, than
if ( a * b + c < fun() ) // is DEPENDENT on not having {now|in future}
// a binary boolean (<)-operator
// a higher priority than (+)-op
so, rather be always explicit and you remain on the safer side.
Finally, test:
RefreshRates(); // Force a state-update
if ( ( aPreviousBALANCE * 1.05 ) < AccountInfoDouble( ACCOUNT_EQUITY ) )
{
...
}
Also check, how are your settings pre-set from the Broker-side - they run a Support-Line for you to ask about their settings:
Equity calculation depends on trading server settings.
Print( "Profit calculation mode for SYMBOL[ ",
Symbol(),
" ] is ",
MarketInfo( Symbol(), MODE_PROFITCALCMODE ),
" { 0: mode-FOREX, 1: mode-CFD, 2: mode-FUTURES }."
);
And where is my AccountBalance() function?
Recent Terminal Builds use a set of new types of calls to:
AccountInfo{Integer|
Double|
String}( <anEnumDrivenItemIDENTIFIER>
)
SymbolInfo{Integer|
Double|
String}( <aSymbolNAME>,
<anEnumDrivenItemIDENTIFIER>
)
to name just a few, so re-read the documentation to adopt the most recent changes. Always. ALAP when your Terminal has got a new Build updated ( might be seen when loading a new version of Help files for the MQL4-IDE and/or Terminal ).
Well, this happens. MQL4 evolves and some features we were used to for ages cease to exist, start to suddenly yield inaccurate or indefinite result or change its behaviour ( ol' MQL4-ers still remember the day, when string data type simply ceased to be a string in silence and suddenly started to become a struct. Ok, it was mentioned somewhere deep inside an almost unrelated page of an updated Help-file, yet the code-crashes were painful and long to debug, analyze and re-factor )