Question

Develop a java program that create an array named grade capable of accepting 10 input grades with decimal point implementing the binary search algorithm. The program accepts element to be searched and display the index of the element once it is found in the array otherwise, display “Not Found”.

Answer 1

Java Arrays

In this tutorial, we will learn to work with arrays in Java. We will learn to declare, initialize, and access array elements with the help of examples.

An array is a collection of similar types of data.

For example, if we want to store the names of 100 people then we can create an array of the string type that can store 100 names.

String[] array = new String[100];

Here, the above array cannot store more than 100 names. The number of values in a Java array is always fixed.

How to declare an array in Java?

In Java, here is how we can declare an array.

dataType[] arrayName;

dataType - it can be primitive data types like int, char, double, byte, etc. or Java objects

arrayName - it is an identifier

For example,

double[] data;

Here, data is an array that can hold values of type double.

But, how many elements can array this hold?

Good question! To define the number of elements that an array can hold, we have to allocate memory for the array in Java. For example,

// declare an array

double[] data;

// allocate memory

data = new Double[10];

Here, the array can store 10 elements. We can also say that the size or length of the array is 10.

In Java, we can declare and allocate memory of an array in one single statement. For example,

double[] data = new double[10];

How to Initialize Arrays in Java?

In Java, we can initialize arrays during declaration. For example,

//declare and initialize and array

int[] age = {12, 4, 5, 2, 5};

Here, we have created an array named age and initialized it with the values inside the curly brackets.

Note that we have not provided the size of the array. In this case, the Java compiler automatically specifies the size by counting the number of elements in the array (i.e. 5).

In the Java array, each memory location is associated with a number. The number is known as an array index. We can also initialize arrays in Java, using the index number. For example,

// declare an array

int[] age = new int[5];

// initialize array

age[0] = 12;

age[1] = 4;

age[2] = 5;

..

Elements are stored in the array

Java Arrays initialization