Java Essentials - Hash table in java

Hach table in Java

So this is the topic in this video. In because of hash table, we'll be storing a key value pair

That means depending upon the current content of the key, we can search for a certain value

So that is the key value pair and that is the main feature in this hash table

So let us go for more further discussion. So the hash table in Java collection

The hash table is a collection that can store the key value pairs

We will choose an object as a key and another object as a value

And then the key is hashed and the resulting hash code is used as an index at which

the item will be stored there. We can get the set of keys present in the hash table by using the method, that is a key set

method using this key set method we can get all the set of keys present in the hash table

and using the method get so this is a get method we can retrieve values from a given key so when

the given key will be there when key will be given then using this get method we can retrieve its respective value stored as a key value pair So for the better clarity let us go for one practical example and using the Java code

will be discussing this hash table into more details. Let us discuss some examples on these hash table and hash table objects

Here we have defined one hash table which will hold the string as string is a string object

as the key and integer object as the value. so we know that hash table contents key value pair so the integer class wraps the

value of the primitive type in an object so there is an integer and here we're

having the string class objects will be there and this is our hash table this

class implements a hash table which maps keys to values any non null object

can be used as a key or as a value here so here we have defined one hash table

class object that is a hash and it has got instantiated with the constructor so with this particular hash

we are going to add some key value pairs here so the respective method is put

so here string is the name is the key and here the respective integer it will be the respective value here so there a marks we actually having so ion 65 depok 80 joy 55 torun 75 and Rahul that is we having

here 70 here so now we are printing this st.h.h. here so let me see that

how the outcomes are coming so the student hash table is having the content that is

that to run 75 you see we added torun at the fourth place and then Joy 55 we

added joy at the third place depok 80 we did this one at the second place

Raul 70 we did that one adding putting this one at the last place and the

on at the first place but you see they the order in which they got added to this

ST hash that is our hash table object the order has not been meant meant

but the key value pair the respective key value pairs that that pair has got

maintained throughout so in this way you have got this one now let us suppose

I want to add another one say I'm going for the ST hash

dot put say if I give a same name say if I go for say joy if I go for say joy

with the value say say seven so initially you see the joy is having the value 55 now it has become 67 then what will happen as a key a key is repeating the same key so it

will it will be not a new entry there it will not put a new values key value

pair there so only the joy its value is marks 55 will be update with the 67

so 55 will get updated with the value 67 so let us go for that you can find

that with this joy we are having the value 67 here okay so key must be unique and that's why it is known as key and

value may repeat and with it with each and every key there should be some one not null

value system dot out of print alien the student hash table and the ST hash we got printed

you see we got printed this one now we're doing something different here so string

max key is equal to null so we are going to hold the name of that student who has secured

the maximum marks so I and T max marks is equal to zero and max key that is the

which will be holding the name is having that null string initialized at first

so for string key colon sth has dot key set so in case of st.hats has dot key set

all the key values will be will be there and for all the keys in the key set

the four