MQL4参考 市场信息 SymbolInfoString

SymbolInfoString

Returns the corresponding property of a specified symbol. There are 2 variants of the function.

1. Immediately returns the property value.

string  SymbolInfoString(
   string                   name,        // Symbol
   ENUM_SYMBOL_INFO_STRING  prop_id      // Property identifier
   );

2. Returns true or false, depending on the success of a function. If successful, the value of the property is placed in a placeholder variable passed by reference in the last parameter.

bool  SymbolInfoString(
   string                   name,        // Symbol
   ENUM_SYMBOL_INFO_STRING  prop_id,     // Property identifier
   string&                  string_var   // Here we accept the property value
   );

Parameters

name

[in] Symbol name.

prop_id

[in] Identifier of a symbol property. The value can be one of the values of the ENUM_SYMBOL_INFO_STRING enumeration.

string_var

[out] Variable of the string type receiving the value of the requested property.

Return Value

The value of string type. In case of execution failure, information about the error can be obtained using GetLastError() function:

  • 4106 - symbol is not selected in "Market Watch" (not found in the list of available ones),
  • 4051 - invalid identifier of a symbol property,
  • 4024 - internal error.

Note

It is recommended to use SymbolInfoTick() if the function is used for getting information about the last tick. It may well be that not a single quote has appeared yet since the terminal is connected to a trading account. In such a case, the requested value will be indefinite.

In most cases, it is enough to use SymbolInfoTick() function allowing a user to receive the values of Ask, Bid, Last, Volume and the time of the last tick's arrival during a single call.