programming in ANSI C-Chapter 8 Character Arrays and Strings

.,Chapter8CharacterArraysandStrings,PROGRAMMINGINANSIC,.,CharacterArrays,Inacharacterarray,eachelementstoresonecharacter.e.g.charc5;c0=H;c1=e;c2=c3=l;c4=o;,c0=72;c1=101;c2=c3=108;c4=111;,.,CharacterArrays-Initialization,Likeothertypeone-dimensionalarrays,thecharacterarraycanbeinitializedinthesameway.e.g.charc5=H,e,l,l,o;Ifthenumberofinitializersislessthanthedeclaredsize,theremainingelementsareinitializedtonullcharacter(0).e.g.charc6=H,e,l,l,o;,.,CharacterArrays-Initialization,Likeothertypeone-dimensionalarrays,thecharacterarraycanbeinitializedinthesameway.e.g.charc5=H,e,l,l,o;Ifthenumberofinitializersismorethanthedeclaredsize,thecomplierwillproduceanerror.e.g.charc4=H,e,l,l,o;,Error:Toomanyinitializersinfunction.,.,CharacterArrays-Initialization,Likeothertypeone-dimensionalarrays,thecharacterarraycanbeinitializedinthesameway.e.g.charc5=H,e,l,l,o;Ifthenumberofinitializersisequaltothedeclaredsize,thesizemaybeomitted.e.g.charc=H,e,l,l,o;,.,CharacterArrays,Thecharacterarraycanbeusedasothertypeone-dimensionalarrays.,main()charc10=I,a,m,h,a,p,p,y;inti;for(i=0;i10;i+)printf(%c,ci);,Iamhappy,.,Strings,Astringisacharacterarray.charc10=I,a,m,h,a,p,p,y;Theactuallengthofthestringisnotalwaysequaltothesizeofthecharacterarray.Infact,weoftenconcerntheactuallengthofastringratherthanthesizeofacharacterarray.charc100=I,a,m,h,a,p,p,y;Thesizeofthecharacterarrayis100,buttheactuallengthofthestringisonly10.,.,Strings,Thearraysizeisoftenmuchlargerthanthesizeofthestringstoredinthearray.Inordertorepresenttheendofthestring,thenullcharacter0isusedastheend-of-stringmarker.charc5=B,o,y;,c3istheend-of-stringmarker0,sotheelementsbeforeitcomposethestring,andthelengthofthestringis3.,.,Strings,Payattentiontothedistinctionofthenullcharacter0,andtheblankspacecharacter,andthefigurecharacter0.TheASCIIvalueof0is0.Itcantbedisplayedandactsastheend-of-stringmarker.TheASCIIvalueofis32.Itcanbeoutputtedasablankandoccupyoneplace.TheASCIIvalueof0is48.Itcanbeoutputtedasafigure.,.,Strings,Whenastringconstantisstoredinmemory,italsousesthenullcharacter0astheend-of-stringmarker.Forexample:WhenthestringHelloisstoredinmemory,itrequires6bytesstorage,andthelastbyteisusedtostorethenullcharacter0.,.,Strings-Initialization,Usingcharacters.charc5=G,o,o,d;Usingstring.charc5=Good;charc5=Good;charc=Good;,Notice:Thearraycconsistsof5elementsbutnot4elements!Thisdeclarationisequivalentto:charc5=Good;Itdifferswithcharc4=Good;,.,Strings-Initialization,Theinitializationoftableofstrings.charfruit7=Apple,Orange,Grape,Pear,Peach;,.,InputandOutput%c,%c,main()charstr6;inti;for(i=0;i-1=aA=32=C0=67=ua=20=05=-53,.,String-HandlingFunctionsstrcmp(),strcmp(str1,str2)Wecantuse=operatortocomparetwostrings.while(st1=str2).changeto:while(strcmp(str1,str2)=0)orwhile(!strcmp(str1,str2),.,String-HandlingFunctionsstrlen(),strlen(str)Function:Returnthelengthofthestring(thenumberofthecharactersofstrexceptthenullcharacter).,Forthesefollowingdeclarations,whatisthevalueofthefunctionstrlen(s)?(1)chars10=A,0,B,C,0,D;(2)chars=tb0willn;(3)chars=x69082n;,1(A),3(tb),1(i),.,String-Program1,Writeaprogramtocalculatethelengthofastring.Dontusethefunctionstrlen().Step1:Declareacharacterarrays100;Step2:Readinastring.Step3:Calculatethenumberofthecharactersbeforethefirstnullcharacterins.Itisthelengthofs.Step4:Outputthevalueofthenumber.,.,String-Program1,main()chars100;inti=0,slen=0;printf(Pleasinputthestring:n);scanf(%s,s);while(si!=0)slen+;i+;printf(Thelengthofstringis:%dn,slen);,while(si!=0),while(si),Pleaseinputthestring:HelloThelengthofstringis5.,Pleaseinputthestring:Howareyou?Thelengthofstringis3.,.,String-Program2,Writeaprogramtoconcatenate2strings.Dontusethefunctionstrcat().Step1:Declaretwocharacterarraysa100,b50;Step2:Readtwostringsintoarraysaandb.Step3:Beginwiththenullcharacterofthearrayatocopyallthecharactersbeforethenullcharacterofarraybintoarraya.Step4:Outputthearraysaandb.,.,String-Program2,main()chara100,b50;inti=0,j=0;printf(Pleasinput2strings:n);scanf(%s%s,a,b);while(ai!=0)i+;while(bj!=0)ai=bj;i+;j+;ai=0;printf(a:%snb:%sn,a,b);,Pleaseinput2strings:Goodboy!a:Goodboy!b:boy!,.,String-Program3,Writeaprogramtoreversethecharactersofastring.Step1:Declareacharacterarraysa50;Step2:Readastringintoa.Step3:Getthesubscriptofthenullcharacterofthearraya,andassignittovariablei.Step4:for(j=0;ji;j+,i-)exchangeaiandaj.,.,String-Program3,main()chara30,ch;inti=0,j=0;printf(Pleasinputthestring:n);sc