Difference between revisions of "Java/C2/if-else/English-timed"

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|  This script has been contributed by TalentSprint. This is Arya Ratish from IIT Bombay, signing off
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Revision as of 09:42, 6 April 2015

Time Narration
00:02 Welcome to the spoken tutorial on If else constructs in java.
00:07 In this tutorial, we will learn:
00:09 * About conditional statements
00:11 * Types of conditional statements and
00:13 * How to use conditional statements in Java programs.
00:18 For this tutorial, we are using:

Ubuntu v 11.10

JDK 1.6 and

Eclipse 3.7.0.

00:27 To follow this tutorial, you should have knowledge of using:
00:31 * Arithmetic, Relational and Logical operators in Java.
00:35 If not, for relevant tutorials, please visit our website which is as shown.
00:42 Conditional statements- You may have to perform different actions for different decisions in your code.
00:48 In such cases you can use conditional statements.
00:52 A conditional statement helps to control the flow of execution of a program.
00:57 In Java, we have the following conditional statements:
01:01 * If statement
01:02 * If...Else statement
01:03 * If...Else if statement
01:05 * Nested If statement
01:06 * Switch statement
01:08 In this tutorial, we will learn about If, If...Else and If...Else If statements in detail.
01:15 if statement: if statement is used to execute a block of statements based on a condition.
01:22 It is called a single conditional statement.
01:26 Syntax for If statement ;
01:28 In the if statement, if the condition is true, the block is executed.
01:34 If the condition is false, the block is skipped and it is not executed.
01:40 Now, let us look at an example to understand how the if statement can be used.
01:45 So, let us switch to eclipse.
01:48 We will write a program to identify whether a person is Minor.
01:53 I have already created a class Person.
01:56 Now, inside the main method, let us declare a variable ‘age’ of type int.
02:02 So, type inside the main method: int space age equal to 20 semicolon.
02:14 Now, we will write an If statement as follows:
02:18 Next line, if within brackets age < 21 open curly brackets. Press Enter.
02:30 Here, we are checking if age is less than 21.
02:34 Whatever is inside the brackets belongs to the if block.
02:38 So, inside the brackets type:
02:41 System dot out dot println within brackets and double quotes The person is Minor semicolon.
02:56 Here, if age is less than 21, then “The person is minor” will be displayed.
03:03 So save and run the file.
03:08 We get the output as follows: "The person is minor".
03:14 In this case, the person's age is 20 which is less than 21.
03:20 So, we got the output as “The person is minor”.
03:24 Now, we will learn about if...else statement.
03:27 If...Else statement is used to execute alternative statements.
03:31 These are based on a single condition.
03:34 Let us look at the syntax for writing If…Else statement.
03:38 If the condition is true, the statement or block of code is executed.
03:44 Else, it executes another statement or block of code.
03:49 We will now see how the If…else statement can be used in a program.
03:54 So, let us switch to the eclipse.
03:57 We will now write a program to identify whether the person is minor or major.
04:03 So, inside the main method, type: int age equal to 25
04:12 then, if within brackets age greater than 21
04:19 within curly brackets, type: System dot out dot println within brackets The person is Major.
04:28 Then type, next line,
04:32 else within curly brackets type:
04:38 System dot out dot println within brackets in double quotes The person is Minor semicolon.
04:51 Here, if age is less than 21, “The person is Minor” will be displayed.
04:58 Else, the “The person is Major” will be displayed.
05:02 So, now let us save and run the program.
05:07 We get the output as: "The person is Major".
05:11 Here, the person's age is 25, which is greater than 21.
05:17 Therefore, the program displayed the output as “The person is Major”.
05:22 If…Else If statement: If…Else If statement is used to execute various set of statements.
05:29 These are based on the two given conditions.
05:33 You can also add more conditions based on your requirement.
05:38 It is also called as branching or decision making statement.
05:43 Now, Let us look at the syntax for writing the If…Else If statement.
05:48 If statement initially checks for condition 1.
05:53 If condition 1 is true, it executes the statement-or-block 1 code.
05:59 Else, it again checks for condition 2.
06:02 If condition 2 is true, it executes statement-or-block 2.
06:09 Else, it executes statement 3 or block code 3.
06:13 In this way, we can extend the code by If…Else blocks.
06:17 These blocks can have multiple conditions.
06:20 The corresponding code will get executed, until it finds the true condition.
06:25 If all the conditions are false, it will execute the final Else section.
06:30 We will see how the If…Else If statement can be used in a program.
06:35 So, switch to Eclipse.
06:37 I have already created a class named Student.
06:40 Let us write a program to identify grade of a student.
06:44 This is done based on the score percentage.
06:47 So, inside the main method, type: int space testScore equal to 70 semicolon.
06:58 The input variable named testScore is used to get the score percentage.
07:05 Next line, type: if within brackets testScore less than 35 then within curly brackets type: System dot out dot println within brackets and double quotes C grade semicolon.
07:28 If the 'testScore' is less than 35, then the program displays "C Grade".
07:34 Next line, type else.
07:37 Next line, if within brackets testScore greater than or equal to 35 AND (&&) testScore less than or equal to 60. Put this whole condition within brackets open curly brackets, press Enter.
08:03 Type: System dot out dot println within brackets B grade semicolon
08:13 Here, the program will check for the second condition in the Else If section.
08:18 If the 'testScore' is between 35 and 60 then the program displays "B Grade".
08:24 Next line, type: else within brackets type: System dot out dot println within brackets and double quotes A grade semicolon.
08:42 So Finally, if both the conditions are false, the program displays “A Grade".
08:48 Now, let us save and run this code.
08:51 We get the output as A Grade.
08:55 In this program, the student’s 'testScore' is 70.
09:00 So the output will be displayed as “A Grade”.
09:02 Now Let us change the testScore to 55.
09:07 Now, save and run this program.
09:10 In this case, the output will be displayed as “B Grade”.
09:16 We can also increase the number of conditions.
09:19 Let us add one more condition after the “B grade” output section.
09:23 So type here,

else, next line, if within brackets testScore greater than or equal to 60 AND (&&) testScore less than or equal to 70.

09:47 Open curly brackets press Enter System dot out dot println within brackets and double quotes O grade semicolon.
10:01 Here, if the 'testScore' is between 60 and 70 the program will display "O Grade".
10:07 Now, change the testScore of the student to 70.
10:12 Now, save and run the file.
10:15 We get the output as follows.
10:17 The program will display the output as “O grade”.
10:20 It is not “A grade” as it displayed before.
10:23 The program will display “A grade” for the testScore greater than 70.
10:28 While coding conditional structures:
10:30 * Always remember to add a semicolon while terminating a statement.
10:35 * But don’t add semicolons after the condition.
10:40 * Add the block of code within curly brackets.
10:43 * Curly braces are optional if the block contains a single statement.
10:49 We have come to the end of this tutorial.
10:51 In this tutorial,
10:53 We have Explained: * conditional statements
10:56 * Listed the types of conditional statements
10:59 * Used conditional statements- if, if...else and if...else if in Java programs.
11:04 Now take an assignment on writing java programs using conditional statements- if, if...else and if...else if statements.
11:12 * Write a java program to compare two values using if statement.
11:17 * Write a java program to check whether the given number is even or odd.

Hint : use if...else statement.

11:23 * Write a java program to find the biggest number among the three numbers.

Hint : use if...else if statement.

11:29 To know more about the Spoken Tutorial project,
11:32 watch the video available at the following link.
11:35 It summarizes the Spoken Tutorial project.
11:38 If you do not have good bandwidth, you can download and watch it.
11:42 The Spoken Tutorial Project team:
11:44 * Conducts workshops using Spoken tutorials.
11:47 * gives certificates for those who pass an online test. For more details, please write to contact AT spoken HYPHEN tutorial DOT org.
11:56 Spoken Tutorial project is a part of the Talk to a Teacher project.
12:00 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
12:06 More information on this mission is available at spoken HYPHEN tutorial DOT org SLASH NMEICT HYPHEN Intro.
12:15 This script has been contributed by TalentSprint. This is Arya Ratish from IIT Bombay, signing off.

Thanks for joining

Contributors and Content Editors

Gaurav, PoojaMoolya, Priyacst, Sandhya.np14, Sneha