My 2ND DSA LAB

2 min readNov 5, 2019

As a week after my first Blog I have attended my 2nd LAB. Which is on the topic on Arrays and it’s properties,uses,methods,Algorithms.

What is an Array?

We can say it is a collection of similar data types. It stores the Fixed-sized sequential collection of Elements of Same data type.It starts Indexing from zero.Means our first Inserted Element will be stored on index 0.

Syntax’s:-

Arrays can be Defined or Created by 3 methods in Java:-

1-array_reference_variable=new data_type[length of array];

2-data_type array_reference_variable=new data_type[ length of array];

3-data_type array_reference_variable={element_0,element_1,element_2,…..,element_n};

data_types={int,String,char etc}

array_reference_variable={Any reference variable we want to create}

n={last element of array}

Use:-

Arrays are fast because they let you directly access a single element’s data in one computer cycle regardless of the size of the array.

Multi-Dimensional Arrays:-

It is an Array of 2 or more than 2 dimensions in Array.Matrices are the Basic main example of Multi-Dimensional Arrays.There are the Extension of 2-D matrices and use additional sub-scripts for indexing.They are very Helpful in Programming.

Syntax:-

It can be Declared by 2 methods in Java.

(i)Indirect Method:-

Declaration:-
data_type[][] Array_name = new data_type[x][y];

For Example:- Int[][] array1=new Int[5][10];

Intialization:-

Array_name[row_index][column_index] = value;

For Example:- array1[0][0]=1;

(ii)Direct Method:-

In this method Declaration and Intialization is done in the same line.

Declaration & Intialization:-

data_type[][] Array_name = { {valueR1C1, valueR1C2, ....}, {valueR2C1, valueR2C2, ....} };