MQL5 ReferenceStandard LibraryStringsCStringToUpper StrLenCopyFillAssignAppendInsertCompareCompareNoCaseLeftRightMidTrimTrimLeftTrimRightClearToUpperToLowerReverseFindFindRevRemoveReplace ToUpper Converts all string characters to uppercase. bool ToUpper() Return Value true - successful, false - cannot convert to uppercase. Clear ToLower