Lists, Stacks, and Queues - Data Structures and Algorithm Analysis - page 119

/ ** Array-basedstackimplementation * /
classAStack<E>implementsStack<E>{

privatestaticfinalintdefaultSize=10;

privateintmaxSize; //Maximumsizeofstack
privateinttop; //IndexfortopObject
privateE[]listArray; //Arrayholdingstack

/ ** Constructors * /
AStack(){this(defaultSize);}
@SuppressWarnings("unchecked")//Genericarrayallocation
AStack(intsize){
maxSize=size;
top=0;
listArray=(E[])newObject[size]; //CreatelistArray

}

/ ** Reinitializestack * /
publicvoidclear(){top=0;}

/ ** Push"it"ontostack * /
publicvoidpush(Eit){
asserttop!=maxSize:"Stackisfull";
listArray[top++]=it;

}

/ ** Removeandtopelement * /
publicEpop(){
asserttop!=0:"Stackisempty";
returnlistArray[--top];

}

/ ** @returnTopelement * /
publicEtopValue(){
asserttop!=0:"Stackisempty";
returnlistArray[top-1];

}

/ ** @returnStacksize * /
publicintlength(){returntop;}
Figure4.19 Array-based stack class implementation.