IF-ELSEIF-ELSE Conditional Statements

Section: Flow Control

Usage

The if and else statements form a control structure for conditional execution. The general syntax involves an if test, followed by zero or more elseif clauses, and finally an optional else clause: 
  if conditional_expression_1
    statements_1
  elseif conditional_expression_2
    statements_2
  elseif conditional_expresiion_3
    statements_3
  ...
  else
    statements_N
  end

Note that a conditional expression is considered true if the real part of the result of the expression contains any non-zero elements (this strange convention is adopted for compatibility with MATLAB).

Examples

Here is an example of a function that uses an if statement 

     if_test.m
function c = if_test(a)
  if (a == 1)
     c = 'one';
  elseif (a==2)
     c = 'two';
  elseif (a==3)
     c = 'three';
  else
     c = 'something else';
  end

Some examples of if_test in action: 

--> if_test(1)

ans = 
one
--> if_test(2)

ans = 
two
--> if_test(3)

ans = 
three
--> if_test(pi)

ans = 
something else