linked lists the push(and pop(operations and how they're usedit' not the underlying mechanism used to implement these operations when would you use linked list as opposed to an array as the implementation of stack or queueone consideration is how accurately you can predict the amount of data the stack or queue will need to hold if this isn' clearthe linked list gives you more flexibility than an array both are fastso speed is probably not major consideration data types and abstraction where does the term abstract data type come fromlet' look at the data type part of it first and then return to abstract data types the phrase data type covers lot of ground it was first applied to built-in types such as int and double this is probably what you first think of when you hear the term when you talk about primitive typeyou're actually referring to two thingsa data item with certain characteristics and permissible operations on that data for exampletype int variables in java can have whole-number values between - , , , and + , , , and the operators +-*/and so on can be applied to them the data type' permissible operations are an inseparable part of its identityunderstanding the type means understanding what operations can be performed on it with the advent of object-oriented programmingyou could now create your own data types using classes some of these data types represent numerical quantities that are used in ways similar to primitive types you canfor exampledefine class for time (with fields for hoursminutesseconds) class for fractions (with numerator and denominator fields)and class for extra-long numbers (characters in string represent the digitsall these classes can be added and subtracted like int and doubleexcept that in java you must use methods with functional notation like add(and sub(rather than operators like and the phrase data type seems to fit naturally with such quantity-oriented classes howeverit is also applied to classes that don' have this quantitative aspect in factany class represents data typein the sense that class is made up of data (fieldsand permissible operations on that data (methodsby extensionwhen data storage structure like stack or queue is represented by classit too can be referred to as data type stack is different in many ways from an intbut they are both defined as certain arrangement of data and set of operations on that data