SysUtils.CompareStr、SysUtils.CompareText - 字符串比较
CompareStr 区分大小写; CompareText 不区分大小写. 举例:
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var
s1,s2: string;
i: Integer;
begin
s1 := 'abc';
s2 := 'adc';
i := CompareStr(s1,s2);
ShowMessage(IntToStr(i)); {-2}

i := CompareText(s1,s2);
ShowMessage(IntToStr(i)); {-2}

s1 := 'abc';
s2 := 'ABC';
i := CompareStr(s1,s2); {CompareStr 区分大小写}
ShowMessage(IntToStr(i)); {32}

i := CompareText(s1,s2); {CompareText 不区分大小写}
ShowMessage(IntToStr(i)); {0}
end;