MATLAB Function Reference

elseif

Conditionally execute statements

Syntax

• if expression1
      statements1
  elseif expression2
      statements2
  end
  

Description

If expression1 evaluates as false and expression2 as true, MATLAB executes the one or more commands denoted here as statements2.

A true expression has either a logical true or nonzero value. For nonscalar expressions, (for example, is matrix A less then matrix B), true means that every element of the resulting matrix has a logical true or nonzero value.

Expressions usually involve relational operations such as (count < limit) or isreal(A). Simple expressions can be combined by logical operators (&,|,~) into compound expressions such as: (count < limit) & ((height - offset) >= 0).

See if for more information.

Remarks

else if, with a space between the else and the if, differs from elseif, with no space. The former introduces a new, nested if, which must have a matching end. The latter is used in a linear sequence of conditional statements with only one terminating end.

The two segments shown below produce identical results. Exactly one of the four assignments to x is executed, depending upon the values of the three logical expressions, A, B, and C.

• if A                           if A
     x = a                           x = a
  else                           elseif B
     if B                            x = b
        x = b                    elseif C
     else                            x = c
         if C                    else
            x = c                    x = d
         else                    end
             x = d
         end
     end
  end
  

Examples

Here is an example showing if, else, and elseif.

• for m = 1:k
      for n = 1:k
          if m == n
              a(m,n) = 2;
          elseif abs(m-n) == 2
              a(m,n) = 1;
          else
              a(m,n) = 0;
          end
      end
  end
  

For k=5 you get the matrix

• a =
  
       2     0     1     0     0
       0     2     0     1     0
       1     0     2     0     1
       0     1     0     2     0
       0     0     1     0     2
  

See Also

if, else, end, for, while, switch, break, return, relational_operators, logical_operators

else

end