Scilab/C2/Conditional-Branching/English

Title of script: Conditional Branching

Author: Anuradha Amrutkar

Keywords: if-then-else, select-case

Visual Cue	Narration
Slide	Welcome to the spoken tutorial on Conditional Branching in Scilab.
Slide	To practice this tutorial open the scilab console window on your computer
Slide	We will discuss two types of Conditional constructs in Scilab that is the "if-then-else" construct and the "select-case conditional" construct.
Slide	The if statement allows us to execute a group of statements if a given condition is satisfied.
Demonstration	Let me give you an example: n = 42, if (n == 42) then disp("The number is forty two") end of if construct.
Narration	Here '=' is the assignment operator, which assigns 42 to the variable n, and '==' is the equality operator, which checks for the equality between the right hand and the left hand side operands.
Narration	In this case n and 42 and gives the result in Boolean.
Narration	Here the comma after the first line is optional, Also the then keyword is optional.
Narration	It can be replaced by a comma or a carriage return.
Narration	The end keyword ends the "if" construct.
Narration	On executing the script, we see the output as follows.
Narration	So far we have seen how to execute a set of statements if a condition is true.
Narration	Now we will see how to execute another set of statements if that condition is false or we may wish to check if some other condition is satisfied.
Demonstration	We can do this by using 'else' or 'elseif' keyword respectively. Here is how we do it (the action is shown)
Demonstration	In this example, 54 is assigned to a variable n and checked for both true condition using 'if' and false condition using 'else' as described:
Demonstration	I will cut this paste in the scilab console hit enter n = 54, if (n == 42) then disp("The number is forty two") elseif (n == 54) then, disp("The number is fifty four") else disp("The number is neither forty two nor fifty four") end
Demonstration	You see the output (output is displayed).
Demonstration	If you notice, the examples shown above are on multiple lines.
Narration	They can also be written in a single line with proper semicolons and commas.
Demonstration	I will cut this and paste in the scilab to execute hit enter x = 3; y = 5; z = 4; if x>5 then disp(x), elseif x>6 then disp(y), else disp(z), end
Narration	The select statement allows to combine several branches in a clear and simple way.
Narration	Depending on the value of a variable, it allows to perform the statement corresponding to the case keyword.
Narration	There can be as many branches as required.
Narration	Let us try with an example.
Demonstration	We will assign 100 to a variable 'n' and check the cases 42, 54 and a default case represented by else cut paste hit enter
Demonstration	n = 100, select n case 42 disp("The number is forty two") case 54 disp("The number is fifty four") else disp("The number is neither forty two nor fifty four") end
Demonstration	Here we see the output . (Shows the output)
Slide	This brings us to the end of this spoken tutorial on Conditional Branching using Scilab.
Slide	In this tutorial we have learnt the if - elseif - else statement and the select statement.
Slide	There are many other functions in Scilab which will be covered in other spoken tutorials.
Slide	Keep watching the Scilab links.
Slide	Spoken Tutorials are part of the Talk to a Teacher project, supported by the National Mission on Education through ICT.
Slide	More information on the same is available at http://spoken-tutorial.org/NMEICT-Intro.

Contributors and Content Editors

Chandrika, PoojaMoolya