MQL5 ReferenceStandard LibraryStringsCStringClear StrLenCopyFillAssignAppendInsertCompareCompareNoCaseLeftRightMidTrimTrimLeftTrimRightClearToUpperToLowerReverseFindFindRevRemoveReplace Clear Clears a string. bool Clear() Return Value true - successful, false - cannot clear a string. TrimRight ToUpper