MQL5 compiler diagnostic
MQL5 undeclared identifier error is compiler code 256. The name is misspelled, outside its scope, missing from an include, or taken from a different language or API generation. Find the declaration that should own the name, correct the identifier or dependency, then compile again.
Open the Coding Agent and choose MQL5 from the language menu.
void LogCurrentSpread()
{
long spread_points=SymbolInfoInteger(_Symbol,SYMBOL_SPREAD);
PrintFormat("%s spread=%d points",_Symbol,spread_points);
}Also searched as: mql5 undeclared identifier error fix.
MetaEditor reports undeclared identifier when the source cannot satisfy the language or API contract at that location. Compile errors prevent creation of the EX5 program until they are resolved.
Start with the first error in the build output. A missing delimiter, declaration, or include can make later lines produce secondary messages that disappear after the root cause is fixed.
Compare the exact failing line with its declaration and the official reference. Keep the compiler line and column in the repair prompt or issue report.
Prefer the correct declaration or MQL5 API over creating a dummy variable with the same name. If the name comes from another file, fix the include boundary and confirm that dependency compiles independently.
Compile after each coherent edit. When the first diagnostic moves or disappears, re-read the remaining list instead of applying stale fixes from the previous build.
Every identifier in the example is either declared locally or provided by the documented MQL5 environment. For a failing name, trace the same declaration path.
A clean compile or a cleared error code does not prove strategy logic, broker compatibility, backtest quality, or live-trading safety. Reproduce the result in the target MetaTrader 5 terminal and account environment.
void LogCurrentSpread()
{
long spread_points=SymbolInfoInteger(_Symbol,SYMBOL_SPREAD);
PrintFormat("%s spread=%d points",_Symbol,spread_points);
}Pineify can generate or revise MQL5 source and use MQL5 compilation diagnostics during the coding workflow. Keep the exact error, source location, program type, and intended behavior in the request so the change remains reviewable.
Open MQL5 Coding AgentPineify does not run your broker terminal, Strategy Tester, market data, or live orders. Validate the final program in your own MetaTrader 5 environment.
Review MQL5 AI Coding Agent capabilities
Record the message, code 256, file, line, and column from MetaEditor 5.
Open the first failing line and inspect the declaration, delimiters, include dependencies, and nearby syntax before touching later messages.
Prefer the correct declaration or MQL5 API over creating a dummy variable with the same name. If the name comes from another file, fix the include boundary and confirm that dependency compiles independently.
Press F7, confirm the compiler result, then run the EA, indicator, or script in the appropriate MetaTrader 5 test environment.
The official MQL5 compilation table defines code 256 as "Undeclared identifier."
No. Fix the first credible root error and compile again. One malformed statement can create several downstream diagnostics.
No. Compilation validates source and type contracts. Runtime behavior, order handling, strategy logic, and broker compatibility require separate tests.
Last verified against the linked official references on . Compile and test the final source in the MetaTrader 5 build, broker, symbol, and account environment you plan to use.
Provide the exact diagnostic and intended behavior, inspect the generated change, compile it, and verify it in your MT5 test environment.
Open MQL5 Coding Agent