When nesting if s, each if must be paired with a matching end .

When using elseif and/or else within an if statement, the general form of the statement is

• if expression1
      statements1
  elseif expression2
      statements2
      statements3
  Arguments
  
  expression
  
  expression is a MATLAB expression, usually consisting of variables or smaller expressions joined by relational operators (e.g., count < limit), or logical functions (e.g., isreal(A)).
  
  Simple expressions can be combined by logical operators (&,|,~) into compound expressions such as the following. MATLAB evaluates compound expressions from left to right, adhering to operator precedence rules.
  (count < limit) & ((height - offset) >= 0)
  statements
  
  statements is one or more MATLAB statements to be executed only if the expression is true or nonzero.
  
  Remarks
  
  Nonscalar Expressions
  
  If the evaluated expression yields a nonscalar value, then every element of this value must be true or nonzero for the entire expression to be considered true. For example, the statement, if (A < B) is true only if each element of matrix A is less than its corresponding element in matrix B. See Example 2, below.
  Partial Evaluation of the expression Argument
  
  Within the context of an if or while expression, MATLAB does not necessarily evaluate all parts of a logical expression. In some cases it is possible, and often advantageous, to determine whether an expression is true or false through only partial evaluation.
  
  For example, if A equals zero in statement 1 below, then the expression evaluates to false, regardless of the value of B. In this case, there is no need to evaluate B and MATLAB does not do so. In statement 2, if A is nonzero, then the expression is true, regardless of B. Again, MATLAB does not evaluate the latter part of the expression.
  
  1)   if (A & B)               2)   if (A | B)
  You can use this property to your advantage to cause MATLAB to evaluate a part of an expression only if a preceding part evaluates to the desired state. Here are some examples.
  
  while (b ~= 0) & (a/b > 18.5)
  if exist('myfun.m') & (myfun(x) >= y)
  if iscell(A) & all(cellfun('isreal', A))
  Examples
  
  Example 1 - Simple if Statement
  
  In this example, if both of the conditions are satisfied, then the student passes the course.
  
  if ((attendance >= 0.90) & (grade_average >= 60))
     pass = 1;
  Example 2 - Nonscalar Expression
  
  Given matrices A and B
  
  A =                 B =
       1     0            1     1
       2     3            3     4
  
  Expression
  
  Evaluates As
  
  Because
  
  false
  
  A(1,1) is not less than B(1,1).
  
  A < (B + 1)
  
  Every element of A is less than that same element of B with 1 added.
  
  false
  
  A(1,2) & B(1,2) is false.
  
  Every element of B is less than 5.