Introduction to programming languages

(recapitulation from the last lecture)

Flow control

• Logical and relational operations

     ==  equal to
     ~=  not equal to
     <   less than  
     <=  less than or equal to
     >   greater than
     >=  greather than or equal to
  
     ~  not
     && and
     || or
     &  element-wise and
     |  element-wise or
    

• Condition

  something that either holds, or does not hold
  values: true or false, stored in logical variables

     a == 3
     3 == a
     (b < 3) & (b > 1)
     C = (b < 3) & (b > 1)
    

• Control flow statements

  C - condition, B, B1, B2 - blocks of statements

  Conditional statement

  complete:

   if C 
     B1
   else
     B2
   end
  
   if C 
     B1
   elseif
     B2
   ...
   else
     B
   end
    

  noncomplete:

   if C
     B
   end
    

  Loop WHILE

  number of repetitons is not known in advance

     while C
       B
     end
  

  Loop FOR

  number of repetitons is known in advance

     for k = 1:n
       B
     end 
  
     v = [1 3 12 -6];
     for k = v
       disp(k)
     end 
  

  FOR command is a special case of the previous command WHILE:

     k = 1;
     while k<=n
       B
       k = k+1;
     end