An interactive introduction to MATLAB

4.2the if-else statement 49

Listing 4.5: basic_if.m - Script to show simple if statement

1 % basic_if.m

2 % Script to show simple if statement

3 %

4 % Craig Warren, 08/07/2010

6 % Variable dictionary

7 % x Variable to hold entered number

9 clear all; % Clear all variables from workspace
10 clc; % Clear command window

12 x = input('Enter a number: '); % Get a number from the user
13 if x>10 % Test if x is greater than
14 disp('Your number is greater than 10')
15 end

Comments:

• On Line 12 theinputcommand is used, which prompts the user for input
  with the requestEnter a number:and assigns the number entered to
  the variablex.


• On Line 13 anifstatement is used with the logical expressionx>10. If this
  expression is true then the textYour number is greater than 10is
  displayed, otherwise if the expression is false nothing is executed.

Theelseandelseifcommands can be used to apply further conditions

to theifstatement. Listing 4.6 presents the syntax of these commands.

Listing 4.6: Syntax of anifstatement withelseandelseif

1 iflogical_expression

2 statements

3 elseif logical_expression

4 statements

5 else

6 statements

7 end

Comments:

• On Line 3 the logical expression associated with theelseifcommand
  will only be evaluated if the preceding logical expression associated with
  theifcommand returns false.


• Notice that the elsecommand on Line 5 has no associated logical
  expression. The statements following theelsecommand will only be