Delphi中要替换字符串的某些字符该怎么做答:function replace(s,sa,sb:string):string;vari,k:integer;temp:string;begink:=length(sa);i:=pos(sa,s);temp:=s;if i<>0 then begintemp:=copy(s,1,i-1)+sb+copy(s,i+k,length(s)-i-k+1);end;replace:=temp;end;beginwriteln(replace('1234AA5678','AA','pppp'));end.