Printformat - MQL4

PrintFormat Function

Formats and enters sets of symbols and values in the Expert Advisor log.

Syntax

void PrintFormat(string format_string, ...);

Parameters

format_string [in]: A string containing plain characters and format specifications (starting with '%').

... [in]: Values of simple types, separated by commas. Maximum 64 parameters including format_string.

Return Value

String (implicitly, as it's printed to log).

Notes

Does not work during Strategy Tester optimization.

Parameter count, order, and types must match format specifications precisely; otherwise, the result is undefined.

printf() can be used as an alternative.

Format specification: %%[flags][width][.precision][{h | l | ll | I32 | I64}]type

#### Format Specification Fields:

**flags**: Control output alignment and sign display.

* -: Left justification. * +: Always show sign. * 0: Zero-padding. * (space): Space before positive signed values. * #: Alternate output form (e.g., 0x prefix for hex).

**width**: Minimum number of output characters. Padded with spaces or zeros based on flags. If *, width is taken from an argument.

**precision**: Number of digits after decimal point for floating-point types, or minimum digits for integers. Can truncate floating-point values.

**{h | l | ll | I32 | I64}**: Data size specifiers for integer types.

**type**: Specifies the output format.

* c, C: Character. * d, i: Signed decimal integer. * u: Unsigned decimal integer. * o: Unsigned octal integer. * x, X: Unsigned hexadecimal integer. * e, E: Scientific notation (double). * f: Fixed-point notation (double). * g, G: Compactest of f or e. * a, A: Hexadecimal floating-point notation. * s, S: String.

Example

// Example demonstrating various format specifiers
string server = AccountInfoString(ACCOUNT_SERVER);
int login = (int)AccountInfoInteger(ACCOUNT_LOGIN);
long leverage = AccountInfoInteger(ACCOUNT_LEVERAGE);
PrintFormat("%s %d: leverage = 1:%I64d", server, login, leverage);
double equity = AccountInfoDouble(ACCOUNT_EQUITY);
string currency = AccountInfoString(ACCOUNT_CURRENCY);
PrintFormat("%s %d: account equity = %.2f %s", server, login, equity, currency);
double profit = AccountInfoDouble(ACCOUNT_PROFIT);
PrintFormat("%s %d: current result for open orders = %+.2f %s", server, login, profit, currency);
double point_value = SymbolInfoDouble(_Symbol, SYMBOL_POINT);
string format_string = StringFormat("%%s: point value = %%.%df", _Digits);
PrintFormat(format_string, _Symbol, point_value);
int spread = (int)SymbolInfoInteger(_Symbol, SYMBOL_SPREAD);
PrintFormat("%s: current spread in points = %d ", _Symbol, spread);PrintFormat("DBL_MAX = %.17e", DBL_MAX);
PrintFormat("EMPTY_VALUE = %.17e", EMPTY_VALUE);
PrintFormat("PrintFormat(EMPTY_VALUE) = %e", EMPTY_VALUE);
Print("Print(EMPTY_VALUE) = ", EMPTY_VALUE);