Java Collections Framework-Part1 | Collection Vs Collection Framework
Summary
TLDRIn this HDT Channel tutorial, Pawan introduces Java's Collections Framework, explaining the concept of a 'collection' as a group of objects. He differentiates between a collection and the framework, which provides classes and interfaces to manage collections. Pawan highlights the limitations of arrays, such as fixed size and the inability to store heterogeneous data, and contrasts them with the flexibility and features of collections like ArrayList and HashMap. The session sets the stage for upcoming in-depth discussions on various collection types and their practical applications in Java.
Takeaways
- 😀 A collection is a general term for a group of objects, like multiple students in a class or employees in an organization.
- 📚 The Java Collections Framework provides a set of interfaces and classes that allow objects to be stored and managed in various ways.
- 🔑 The main difference between a collection and the Collections Framework is that the former is a general term, while the latter is a set of tools in Java for managing collections.
- 🚫 Arrays in Java have limitations such as fixed size and the inability to store heterogeneous data types.
- 🛠 The Collections Framework overcomes the limitations of arrays by offering growable, flexible data structures that can store various data types.
- 🌐 The framework includes classes and interfaces like ArrayList, HashMap, TreeMap, Stack, and LinkedList, each with its own specific use cases.
- 💡 The Collections Framework is beneficial because it provides ready-made methods for common operations, such as sorting and searching, without the need for custom logic.
- 📈 The flexibility of the Collections Framework allows for dynamic resizing, which is not possible with fixed-size arrays.
- 🔄 It supports both homogeneous (same data type) and heterogeneous (different data types) data storage, making it more versatile than arrays.
- 🔑 The framework uses underlying data structures to implement its classes and interfaces, which is why it can offer a rich set of methods for manipulating collections.
Q & A
What is the basic definition of a 'collection' as mentioned in the script?
-A 'collection' is a general term used to represent a group of objects as a single entity. For example, multiple students in a class can be referred to as a collection of students.
What is the Java Collections Framework and how does it differ from a simple collection?
-The Java Collections Framework is a set of interfaces and classes that allow objects to be stored and managed in various ways. It differs from a simple collection by providing a structured way to handle groups of objects with methods for operations like sorting and searching.
Why do we need the Java Collections Framework according to the script?
-We need the Java Collections Framework to overcome the limitations of arrays, such as fixed size, inability to store heterogeneous data, and lack of ready-made methods for operations like sorting and searching.
What are the limitations of arrays as discussed in the script?
-Arrays have limitations such as being of fixed size, not being growable at runtime, and only allowing the storage of homogeneous data types.
How does the script illustrate the concept of storing multiple elements using an array?
-The script illustrates storing multiple elements using an array by creating an array of integers where each index represents a memory location that can hold a value, allowing multiple values to be stored in a single variable.
What is the difference between homogeneous and heterogeneous data as explained in the script?
-Homogeneous data refers to an array or collection that can only store elements of the same data type, whereas heterogeneous data means a collection can store elements of different data types.
How does the script explain the concept of an 'object array' in Java?
-An 'object array' in Java is an array that can hold objects of any type, allowing for the storage of both homogeneous and heterogeneous data. This is in contrast to a primitive type array, which can only hold values of a specific primitive type.
What are the advantages of using the Java Collections Framework over arrays as mentioned in the script?
-The Java Collections Framework offers advantages such as dynamic sizing, the ability to store both homogeneous and heterogeneous data, and the availability of ready-made methods for common operations like sorting and searching.
What are some of the classes and interfaces available in the Java Collections Framework as hinted in the script?
-Some of the classes and interfaces available in the Java Collections Framework include ArrayList, List, HashMap, Hashtable, TreeMap, Stack, and LinkedList.
How does the script suggest overcoming the limitations of arrays?
-The script suggests overcoming the limitations of arrays by using the Java Collections Framework, which provides classes and interfaces that allow for dynamic sizing, storage of mixed data types, and built-in methods for various operations.
Outlines
📚 Introduction to Java Collections
The speaker, Pawan from HDT Channel, introduces the topic of Java Collections Framework. He explains the basic concept of a 'collection' as a group of objects, using examples such as students in a class or employees in an organization. The session aims to clarify the difference between a collection, which is a group of objects, and the collection framework, which is a set of classes and interfaces in Java that allow these groups of objects to be represented as single entities. The speaker emphasizes the need for the collection framework to efficiently manage groups of objects in Java programs.
🔑 Understanding Java's Collection Framework
Pawan further elaborates on the Java Collections Framework, contrasting it with the limitations of arrays. He points out that arrays can only hold a fixed number of elements and are limited to storing homogeneous data types. To overcome these limitations, the collection framework provides various classes and interfaces like ArrayList, HashMap, and others. The framework allows for dynamic sizing and the storage of both homogeneous and heterogeneous data types. The speaker also touches upon the lack of built-in methods in arrays for operations like sorting or searching, which are available in the collection framework.
🚫 Limitations of Arrays in Java
This section discusses the specific limitations of arrays in Java, such as their fixed size, which means they cannot grow or shrink at runtime. This inflexibility can lead to wasted memory if the array size is overestimated or an 'IndexOutOfBoundsException' if more elements are added than the array can hold. Additionally, arrays can only store homogeneous data, restricting the types of elements they can contain. The speaker also mentions that arrays do not utilize underlying data structure concepts, which means there are no ready-made methods for common operations, requiring custom logic for tasks like sorting or searching.
🌟 Advantages of Collections Over Arrays
Pawan highlights the advantages of using collections over arrays. Collections are growable, allowing for dynamic addition and removal of elements without the risk of memory wastage. They can store both homogeneous and heterogeneous data, providing more flexibility in data storage. Furthermore, collections are implemented with underlying data structures that provide ready-made methods for operations like sorting and searching, eliminating the need for custom programming logic. The speaker sets the stage for upcoming sessions that will delve deeper into the different types of collections available in Java.
🔍 Overview of Java Collections Framework
In the concluding part, Pawan summarizes the introduction to Java Collections, emphasizing the need for the collection framework due to the limitations of arrays. He outlines the benefits of the framework, such as its growable nature, ability to handle diverse data types, and the presence of built-in methods for common operations. The speaker also hints at future sessions that will explore various collection types, classes, and interfaces in detail, providing a comprehensive understanding of how to work with Java Collections.
Mindmap
Keywords
💡Collection
💡Collection Framework
💡ArrayList
💡Homogeneous Data
💡Heterogeneous Data
💡Fixed Size
💡Growable
💡Underlying Data Structure
💡Ready-Made Methods
💡Object Array
Highlights
Introduction to Java Collections Framework
Definition of a Collection as a group of objects
Explanation of Collection Framework comprising classes and interfaces
Differentiation between Collection and Collection Framework
Example of representing multiple students as a Collection
Use of ArrayList to represent a Collection of elements
Rationale behind needing a Collection Framework in Java
Demonstration of variable declaration and value assignment in Java
Limitations of Arrays in Java such as fixed size and homogeneous data storage
Concept of Object Array to overcome limitations of Arrays
Advantages of Collection over Arrays in terms of size flexibility
Ability of Collections to store both homogeneous and heterogeneous data
Availability of ready-made methods in Collections due to underlying data structures
Comparison between Arrays and Collections highlighting their differences
Introduction to various Collection types like ArrayList, HashMap, and more
Overview of upcoming sessions covering detailed exploration of Collection types
Transcripts
hello everyone welcome you all this is pawan from hdt channel so from today onwards we are going to
see java collections framework so as part of today's session we'll see some detection part
like what is collection and what is collection framework and what are the different collection
types are available in java right so first of all let us start with what is collection
so what is a collection so first let us try to understand this term what is collection
so this is basic general term which you can use commonly like group of objects is a collection so
for example let us say i have multiple students in the class it's a student 1 and student 2
and student 3 so all together we can call as a collection of students
and similarly when i take an organization we have a multiple employees let's say employee one
employee two and employee three and so on so all of them comes under one collection so collection
of employees similarly collection of pins or collection of animals so we can use this
collection term in general so that representing a group of objects so that is simple definition what
is meant by collection so collection is a group of objects and the collection is representing
it is a single entity which is representing multiple objects collection is a single entity
which is representing multiple objects but what about the collection framework so in java
uh to represent group of objects into a single entity we need certain number of classes and
interfaces so collection framework which will provide you those classes and interfaces so what
is collection framework means it defines the different interfaces and classes by
which we can represent group of objects into a collection so that is a basic difference between
collection and collection framework so let me just repeat once again with some examples
so what is a collection and collection framework so for example let us say
a collection so i have a student one and i have another student two and i have another
student three so i have a three students so collectively i will call as a one collection
collectively i have called as a one collection so to representing this collection or to
representing a group of element we need a collection so how we can represent a group
of element into single entity we need a special classes or interface so for example in java
so we have something called arraylist so when i say arraylist equal to new arraylist when i
create an object like this i can store a group of elements into error list so this is a one
example of the collection framework so the collection framework is a group of classes
and interfaces by which we can represent a group of objects into single entity so that is the basic
difference between collection and collection framework so before discussing the collection
framework first of all we need to know why we need to go for collection framework why we need to have
a collection framework in java so to understand this better let us see one example suppose in java
so if you want to uh store a value into a variable so first we will define like this so first we will
have some data type and then we define some variable name let's say a and here i'll say
something called 10 so what exactly this is representing int is a data type and a is a
variable 10 is a value and similarly if i want to store one more value into a variable so again i
have to define one more variable and then i can store some other value similarly if you want to
store 100 numbers like this so 100 variables we have to create so to store 100 variables we have
to create to store 100 values we need to create 100 variables so this is a not a best programming
practice so it is not a best programming practice so what we have to do is
to representing many numbers so here let us conserve this each and every value is one object
to representing these all the values we will create a one variable let us say i will create
one small variable by using array so when x for example let us say integer a and equal to
new int and here i'll say 100 so when i create an array variable like this in java
so there is a single variable which can hold multiple values that means it can hold group of
elements or group of objects so here every element so for example if i create 100 like this which
will create 100 memory locations like this let us say here starting from 0 index is starting from 0
1 2 3 so 100 locations it will be created so in each and every location we can put some value or
sometimes we can also store object elements so we can use this array which will representing
or which can store multiple elements or multiple objects so is it it is clear till here
because the collection is nothing but to representing the group of elements
as a single entity which is a collection so if i just look at this example
so we can achieve this somehow by using array concept because here if i if i specify the size
here so you can store some group of elements into a single variable so if you if you have some value
here 10 if you want to access this value so we can say a of zero so by using this index number
i can access the values from this array so if you just look at this example
in array concept we have certain limitations so what are those limitations we have in this area
so now we will discuss this because to overcome those limitations corrections framework framework
come into picture so what are the problems with the arrays concept so let us see here
i created one array let's say int a and equal to new end of here i can say some size let us say
i put some 10 so when i say 10 here which will create 10 different locations
and array will be created like this and 10 rows will be created index will start from 0
so 0 1 2 and the last index will be 9 because the index will start from 0 so the last index
will be n minus 1 always so it is 9 here so we can store different elements here 10 or 20 30 40 and
so on so this is normal array concept so in this array concept what is the problem with this is
when i create an array like this in the array we can store homogeneous data only so what is
homogeneous data means we can store only same group of elements so same kind of elements
so that means if array is defined with the integer type i can store only numbers in that suppose if
i create this array with double or string type i can store only string on that so that means
array will allow us to store only homogeneous data so homogeneous data in the sense the same
kind of data similarly if i create a array with a student class object let us say here student
stu and equal to new student of i'll say 10 now observe this instead of data type i use
some class here student so when i create array like this student sto is an array
and new student of 10 so in this particular array so which will create 10 locations
right which will create a 10 location let's say 0 1 2 and so on so in every location we can we can
store some student object details like here one object we can store and here one object another
object we can store or here we can store another object so again here if you just look at here
when i create an array with the student type i can store only student information in those locations
it can hold only student objects but here when i create a student stu and here i'll say new
i'll say customer so this is a different class so this cannot hold now because the array can hold
only homogeneous data so homogeneous data means the all the data elements should be the same type
so we cannot store multiple data elements in the array so this is a one limitation we have this in
array but still we can overcome this limitation by creating object array so instead of creating
the into or instead of for specifying the student specifically if i create an object array which can
hold everything so for example let me create an object let me create array with the object type
so this is called object array so now a is created let's say new [Music]
so let me just say like this this is an object array so new object now observe this so here i'll
say 5 so now i created an object array so when i create an object array i can store homogeneous
data as well as heterogeneous data that means it can hold same data type elements and i can also
store multiple data type of elements so for example so it will create multiple locations
five locations and here i can put number or here i can put decimal number or you can here i can
put a string and so on similarly a different type of objects also we can store in this array
so somehow we can achieve this we can overcome this problem by using object array so here also
we are representing group of objects into a single entity so group of objects into a single entity
so this is also a kind of a collection now we'll see the what is the problem with this array so
based on this problem we can overcome this problem by using collections concept so when
i take this array concept so the first problem with this is the first problem with the array is
the array is having a limited size so for example when i say 5 that value is a fixed so i cannot
store more than 5 values so array is fixed in size so at the runtime i cannot increase or
decrease the size so five is a fixed size so when i define the array that the size is fixed so it
will create five elements so it can create five store five memory locations and i can store only
five elements into this array and if you are trying to store one more element it will throw
an exception like error index out of one exception so that is a problem suppose if i created five
elements in the array five memory locations i created and if i store only three elements when
i store only three elements and rest of the spaces will be wasted so this is a one problem with the
array so array size is always fixed so at the runtime we cannot increase or decrease the size
and suppose if we want to store more than these elements still there is a problem and if i store
less number of elements still the memory will be wasted so this is the one problem with the array
and the second problem is the second problem is so what does that mean is array is a fixed in size
means it is not growable so these are technical terms like arrays are not growable in nature
so that means at the run time we cannot increase or we cannot decrease the
size of an array so that is that means array is a not growable in nature it is not growable in
nature this is a first problem so the second problem with the array is size is fixed and
second problem is we can store only same data type of element that means homogeneous data
okay only homogeneous data we can store in this area only homogeneous data that means
same data type of elements we can store in this array there's a second problem
and we already seen sizes fixed because at the runtime we cannot increase and we cannot decrease
the size and they are not growable in nature so these are the two problems the third problem is
so while implementing the arrays they have not basically used any data structure underlying
data structure concept so while implementing the arrays in java they are not basically using an
underlying data structure concept so we cannot it cannot support any ready-made methods we
can say ready-made methods what is ready-made methods means suppose when i create an array
right if i want to sort some elements or if you want to set some element is there in the
array or not i need to write a logic for that i don't have any predefined methods for that
okay so because the arrays have implemented no arrays are not implemented by using any underlying
data structure so that is a problem so the reading ready-made methods are not there in the arrays
so this is one more problem so arrays are in fixed in size and error arrays hold only
homogeneous data and arrays are not implemented by using any data underlying data structure
so we don't have ready-made methods we cannot use those methods and if you want to do any operations
on the arrays we have to write a programming logic so this is a these are the basic problems with the
normal arrays concept so to overcome these problems to overcome these problems we have
collections available in java so collections framework so now we will discuss why we need a
collection so in the normal arrays concept we have these problems so we have in fixed size we can
store only homogeneous data and they don't have any underlying data structure so we cannot use any
ready-made methods so when you come to the collection framework so collection framework
so java in the collection framework they have provided certain number of classes interfaces
so we have something called arraylist and we have something called list is
also an interface which is realistic derived from the list and we have something called
hash map and we have something called okay so hash table and we have something called tree
stack and so on so there are so many classes and interfaces are available so by using all these
types right we can maintain the we can store a group of elements into a single entity so what are
the additional advantages we will get when you use the collection types over arrays concept so far we
have seen arrays concept how we can store multiple data type of elements and also we have seen what
are the limitations we have in this array right so now i will show you how we can overcome those
problems by using this collection types so let us try to compare arrays and collection so why we
need to go for arrays because in arrays we have some limitations to overcome those limitations
we go for collection concept so well let us compare with erase and collection
array and collections so collection in the sense it can be any collection like it can be array
list hash map vector tree whatever linker list everything all that comes under the collections
now what are the basic differences between collections and errors concept so we have
noticed we have some limitations in array so what what is the first limitation is a fixed size
so if you want to create an array before that we need to know how many elements we are going
to store in this array and then we can create an array we can proceed further so the size is fixed
at the runtime if you want to add a new values or if you want to remove the existing values
it is not possible in this areas concept okay so we have to write a programming logic so fixed size
so the runtime we cannot increase or decrease the size and if you want to store more than more
elements than the size it will throw an exception similarly if you want to store a less number of
elements based on the size suppose if i say size is 10 if i store only 5 elements still the rest of
the memory will be wasted so basically areas are not growable in nature but whereas in collection
they are growable in nature growable in nature so what does it mean is at the runtime
if you want to add a new elements we can still keep on adding a new data elements and similarly
if you want to reduce the elements if you want to remove the elements at the random we can remove
the element so because of the removing there is no memory wasted will be there so collections
are growable in nature whereas arrays are not growable so that is fixed size there is
a first difference and now come to the second difference is arrays can hold homogeneous data
it is can hold homogeneous homogeneous data when you come to the collections
it can hold homogeneous data homogeneous data plus heterogeneous data heterogeneous in the data
means it is can have all kinds of data elements so different data type of elements can store
so that is an one more advantage of collection framework so homogeneous data plus heterogeneous
data also can be stored in the collection so there's a second one so third difference is
in the normal arrays concept so because arrays are not implemented based on by using any data
structure underlying data structure so ready-made methods are not there so if i create an array if
you want to search an element if you want to sort an elements we have to write a programming logic
okay so that means there is no underlying structure so there is no underlaying
underlying data structures so there is no ready-made methods available so ready-made methods
not available if you want to do any operations on java we have to write a programming logic for that
but when you come to the collections the collections are implemented
by using some data structure underlying data structure so so it is implemented
by using data structure underlying data structure so that means the ready-made methods are available
so ready-made methods are available so what is ready-made methods means for example
if i create a normal array right so if you want to sort or if you want to search in elements in this
array we have to write a programming logic for that so instead of a when i create an error list
right so when i create an error list basically what is an error list real list is a collection
so when i create an error list so we don't need to write a such logic for that so we have a ready
methods or this or sort or search so we have a ready-made methods are there so by using
those ready-made methods we can do different operations on the collection so that means so
there is no underlying data structure for the arrays concept whereas in the collection all
types of collections are implemented by using some underlying data structures so that's the reason
the ready-made methods are available so for every collection there are certain methods are available
by using those methods we can perform certain operations on the collections so this is
the way we need to understand what exactly collection means and collection framework and
what are the different classes and interfaces are available in the collection framework
right so this is basically introduction part of the collections and in the coming sessions
i will show you we will see how we can learn uh what are the different type of collections
how we can work with the array list hash map a tree vector so all types of collections what are
the different classes are available what are the different type of interfaces are available so we
will see all kinds of things from the collection framework okay so this is the introduction part
what exactly collection means collection framework means and what is the difference
between collection and correction framework and why we need a collection framework and what are
the different collection classes and interfaces are available all right so that's all for this
Browse More Related Video
Java Collections Framework-Part2 | Interfaces And Classes
Data Types in Java | Master DSA in Java
DATA TYPES in Python (Numbers, Strings, Lists, Dictionary, Tuples, Sets) - Python for Beginners
Arrays | Godot GDScript Tutorial | Ep 10
Stage 5 #4 Number Classes like BigInteger And Javadoc Comments
DAY 10 | PHP AND MYSQL | VI SEM | B.CA | ACCESSING MYSQL | L1
5.0 / 5 (0 votes)