Java/C2/Introduction-to-Array/English

Title of script: Introduction to Arrays

Author: TalentSprint

Keywords: arrays, java, video tutorial

Visual Cue	Description
Slide 1 Welcome	Welcome to the spoken tutorial on Introduction to Arrays.
Slide 2 Learning Outcomes	In this tutorial, you will learn how to create arrays and access elements in arrays.
Slide 3 Tools Used	For this tutorial we are using Ubuntu 11.10 JDK 1.6 and Eclipse 3.7.0
Slide 4 Prerequisites	For this tutorial, you should have knowledge of data types and for loop in Java. If not, for relevant tutorial please visit our website which as shown.
Slide 5 and 6 Arrays Highlight index column as you explain.	Arrays are a collection of data. For example, a list of marks, a list of names, a list of temperatures or as shown on the slide, a list of numbers. Each item has an index based on its position. The index of the first element is 0. The second element has index 1 and so on. Let us now see how to store this data. So switch to Eclipse.
Minimize Slides and open Eclipse Eclipse should contain the following code public class ArraysDemo{ public static void main(String[] args){ } }	A class named ArraysDemo has already been created. Within the main method, let us add the rainfall data.
Inside main function, type int rainfall[] = {25, 31, 29, 13, 27, 35, 12};	Inside main function, type int rainfall open close square brackets equal to within curly brackets 25, 31, 29, 13, 27, 35, 12 semicolon. Note the square braces after the variable name rainfall. This declares rainfall as an array of integers. The braces are used to specify the elements of the array. Now let us access data.
In the next line, type System.out.println(rainfall[2]); Highlight as you explain.	Next line, type System dot out dot println within brackets rainfall then within square brackets 2 semicolon. We are printing the element with index 2. In other words, the third element in the array. Let us now run the code.
Save and run. Highlight the ouput	As we can see, the output is the third value, 29. Now let us try a different index.
Change rainfall[2] to rainfall[0] save and run. Point to output	Change 2 to 0 As we can see, the output is the first value. Now let us modify a value.
Before the Syste... line, type rainfall[0] = 11; save and run. Point to output	We shall change the value of the first item. Type rainfall[0] = 11; Now let us see its value. As we can see, the value has been changed to 11.
	Now what if we only know the size of the array and do not know the values. Let us see how to create such array.
	Remove everything in main function and type int squares[] = new int[10]; This statement creates an array of 10 inetgers called squares. Now let us add some values.
In the next line, type squares[0] = 1; squares[1] = 4; squares[2] = 9; squares[3] = 16;	Type squares[0] = 1; squares[1] = 4; squares[2] = 9; squares[3] = 16; We have entered the squares of first four numbers. Now what about the other elements of the array. Let us see what they contain.
In the next line, type System.out.println(squares[5]);	We shall print the sixth value in the array. Type System.out.println(squares[5]);
Save and run. Point to output	We see that the value is zero. This is because when we create an array of integers, all the values are initialized to 0. Similarly an array of floats will have all its values initialized to 0.0. It would be a long process if we have to type each value into the array. Instead, let us use a for loop.
After the squares[3] line, type int n, x; for(x = 4, x < 10, x = x + 1){ n = x + 1; squares[x] = n * n }	Type int n, x; for(x = 4, x < 10, x = x + 1){ n = x + 1; squares[x] = n * n } We iterate over numbers from 4 to 9 and set the corresponding element in the array. Now let us see the output.
Save and run. Point to output	As we can see, the sixth element now is the square of 6, which is 36. In fact now we can set all the values inside the for loop.
Remove all the lines from squares[0]... to squares[3]... Change x = 4 to x = 0 Change println(squares[5]) to println(squares[2]) save and run. Point to output	Remove the lines that set the values manually and change 4 to 0 This way all the elements from index 0 to index 9 are set to the corresponding squares. We shall now see the value of the third element. change 5 to 2 Save and run As we can see, the value of third element has been set in the loop and it is 9.
	This way, arrays can be created and used.
Minimize the Eclipse window and switch to slides. Slide 7 Summary	We have come to the end of this tutorial. In this tutorial we have learnt how to use for loop in java.
Slide 8Assignment	The assignment for this tutorial is, Given an array of integers, find the sum of all the elements in the array.
Slide 9About the Spoken Tutorial Project Watch the video available at[1]http://spoken-tutorial.org/What_is_a_Spoken_Tutorial It summarises the Spoken Tutorial project If you do not have good bandwidth, you can download and watch it	To know more about the Spoken Tutorial project, watch the video available at the following link. It summarises the project.If you do not have good bandwidth, you can download and watch it.
Slide 10Spoken Tutorial WorkshopsThe Spoken Tutorial Project Team Conducts workshops using spoken tutorials Gives certificates for those who pass an online test For more details, please write to contact@spoken-tutorial.org	The Spoken Tutorial Project Team. Conducts workshops using spoken tutorials and gives certificates for those who pass an online test. For more details, please write to contact AT spoken HYPHEN tutorial DOT org.
Slide 11Acknowledgement Spoken Tutorial Project is a part of the Talk to a Teacher project It is supported by the National Mission on Education through ICT, MHRD, Government of India More information on this Mission is available at http://spoken-tutorial.org/NMEICT-Intro	Spoken Tutorial Project is a part of the Talk to a Teacher project and is supported by the National Mission on Education through ICT, MHRD, Government of India. More information on this Mission is available at spoken HYPHEN tutorial DOT org SLASH NMEICT HYPHEN Intro
Slide 12About the contributor This script has been contributed by TalentSprint www.talentsprint.com Thanks for joining	This script has been contributed by TalentSprint. This is Prathamesh Salunke signing off. Thanks for joining.

Contributors and Content Editors

Arya Ratish, Pratham920, Sneha