Java/C2/Introduction-to-Array/Gujarati

Time	Narration
00:02	Welcome to the spoken tutorial on Introduction to Arrays.
00:07	In this tutorial, you will learn how to create arrays and access elements in arrays.
00:14	For this tutorial we are using Ubuntu 11.10 JDK 1.6 and Eclipse 3.7.0
00:25	For this tutorial, you should have knowledge of data types and for loop in Java.
00:32	If not, for relevant tutorial please visit our website which as shown.
00:38	Arrays are a collection of data.
00:40	For example, a list of marks, a list of names, a list of temperatures, a list of rainfall,
00:47	Each item has an index based on its position.
00:52	The index of the first element is 0.
00:55	The index of the second element is 1 and so on.
00:59	Let us now see how to store this data.
01:03	So switch to Eclipse.
01:06	A class named ArraysDemo has already been created.
01:11	Within the main method, let us add the rainfall data.
01:16	So Inside main function, type
01:18	int rainfall open and close brackets equal to within curly brackets type 25, 31, 29, 13, 27, 35, 12 and finally a semicolon.
01:53	Note the square braces after the variable name rainfall.
01:58	This declares rainfall as an array of integers.
02:03	The braces are used to specify the elements of the array.
02:09	let us now access data.
02:12	So on the Next line, type
02:14	System dot out dot println rainfall in square brackets type 2
02:28	We are printing the element with the index number 2.
02:32	In other words, the third element in the array i.e.29.
02:38	Let us save run the program
02:43	As we can see, the output is the third element,i.e 29.
02:49	Now let us type 0 in place of 2
02:56	Save and run the program
03:00	As we can see, the output is the first value i.e 25
03:07	Now let us modify the value of the first item
03:13	So type rainfall [0] = 11;
03:27	Now let us see its value. So save and run the program
03:34	As we can see, the value has been changed to 11.
03:40	Now what if we know only the size of the array and do not know the values.
03:45	Let us see how to create such array.
03:49	Remove everything in main function and type
03:57	int squares [] = new int [10];
04:19	This statement creates an array of integers having 10 elements. The name of the array is squares.
04:30	Now let us add some values to it
04:33	So Type
04:35	squares[0] = 1;
04:43	Next linesquares[1] = 4;
04:53	Next linesquares[2] = 9;
05:04	squares[3] = 16;
05:15	So We have entered the squares of first four numbers.
05:20	Now what about the other elements of the array. Let us see what they contain.
05:26	So We shall print the sixth value in the array.
05:30	Type System.out.println(squares [5]);
05:56	Save and run the program.We see that the value is zero.
06:05	This is because when we create an array of integers, all the values are initialized to 0.
06:11	Similarly an array of floats will have all its values initialized to 0.0.
06:18	It would be a long process if we have to type each value into the array. Instead, let us use a for loop.
06:28	So Type int n, x ; for(x = 4; x < 10; x = x + 1){ n = x + 1; squares [x] = n * n; }
07:25	So We iterate over numbers from 4 to 9 and set the corresponding element in the array.
07:36	Now let us see the output.
07:38	As we can see, we are printing the value of sixth element in array SoSave and run.
07:52	We see the sixth element is now square of 6, which is 36.
07:57	In fact now we can set all the values inside the for loop.
08:03	Remove the lines that set the values manually and change 4 to 0
08:14	This way all the elements from index 0 to 9 are set to the corresponding squares.
08:21	We shall now see the value of the third element.
08:25	So change 5 to 2
08:30	Save and run
08:35	As we can see, the value of the third element has been set in the loop and it is 9.
08:42	This way, arrays can be created and used.
08:50	We have come to the end of this tutorial.
08:53	In this tutorial we have learnt
08:55	TO declare and initialize the array ,
08:58	And access element in an array
09:01	The assignment for this tutorial is,
09:04	Given an array of integers, find the sum of all the elements in the array.
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