c语言函数参数为数组指针（ArraysandPointersinCFunctionParameters）

ArraysandPointersinCFunctionParameters

Introduction

WhenworkingwitharraysinC,it'ssometimesnecessarytopassanarrayintoafunctionasaparameter.Sincearraysareessentiallypointerstothememorylocationofthefirstelementinthearray,passinganarrayintoafunctioncanbedoneintwoways:bypassingthearrayitselforbypassingapointertothearray.Thisarticlewillfocusonthelattercase,wherethefunctionparameterisanarraypointer.

ArrayPointersasFunctionParameters

TopassanarraypointerasafunctionparameterinC,simplydeclaretheparameterasapointertotheappropriatedatatype.Forexample,ifyouwanttopassanarrayofintegersintoafunction,thefunctionprototypewouldlooklikethis: ```c voidmyFunction(int*myArray); ``` Insidethefunction,youcanthenaccessthearrayelementsusingpointerarithmetic.Forexample,toprintoutalloftheelementsinthearray,youcoulddosomethinglikethis: ```c voidmyFunction(int*myArray){ inti; for(i=0;iPassingArrayPointersfromMain

Whencallingafunctionthattakesanarraypointerasaparameter,youcanpassthearrayinafewdifferentways.Onewayistodeclareanarrayinthemainfunctionandpassapointertothatarrayintothefunction.Forexample: ```c intmain(){ intmyArray[5]={1,2,3,4,5}; myFunction(myArray); return0; } ``` Anotherwaytopassanarraypointerintoafunctionistodynamicallyallocatememoryforthearrayandthenpassapointertothatmemoryintothefunction.Forexample: ```c intmain(){ int*myArray; myArray=(int*)malloc(5*sizeof(int)); myArray[0]=1; myArray[1]=2; myArray[2]=3; myArray[3]=4; myArray[4]=5; myFunction(myArray); return0; } ```

BenefitsandDrawbacks

Onebenefitofpassingarraypointerstofunctionsisthatitallowsyoutomanipulatethecontentsofthearraywithinthefunction.Forexample,youcouldwriteafunctiontosortanarrayofintegersinascendingorder,andthencallthatfunctionfrommaintosortanarraythatwasdeclaredwithinmain. However,therearealsodrawbackstopassingarraypointersintofunctions.Onedrawbackisthatitcanbedifficulttokeeptrackofthesizeofthearraywithinthefunction.Intheexamplesabove,thesizeofthearraywasknownaheadoftime,butifthesizeofthearrayisnotknown,itcanbedifficulttosafelyaccessalloftheelementsofthearraywithoutcausingasegmentationfault.

Conclusion

PassingarraysasfunctionparametersinCcanbedonebyeitherpassingthearrayitselforbypassingapointertothearray.Whenpassingapointertoanarray,it'simportanttodeclarethefunctionparameterasapointertotheappropriatedatatypeandtousepointerarithmetictoaccesstheelementsofthearraywithinthefunction.Whiletherearebenefitstopassingarraysaspointers,therearealsodrawbacks,suchasthedifficultyofkeepingtrackofthesizeofthearraywithinthefunction.