nested if else statements

Can someone write an example of a nested if else statement? matlab keeps underlining the 'else' when I try to write a nested 'if else' statement telling me the syntax is wrong.

Also, where do I put the 'end' for each of the 'if else' statements?

[Jan]

It would be more useful, if you show us your failing code, such that we can suggest a precisely matching solution.

[Simone Kolb]

you're probably missing "end" to close the conditional

[Rohit Bhagwat]

Yes I have rechecked it many times, the number of 'if' and 'else' statements are perfectly matching, still it shows that one of the if statements does not find a end

[Walter Roberson]

Rohit, it is difficult for us to give an informed opinion without seeing the file in question.

[BISHMITA SHARMA]

May be u are writing the expression in the next line after 'ifelse' try writing it in the same line... because there will be only one 'end', for the first 'if'

[Jan]

@BISHMITA SHARMA: I assume the problem is solved already, because this thread was written 4 years ago.

Answer 1

[Evan]

x = 5.5

if x > 6
    disp('x is greater than 6')
elseif x >= 3 && x <= 6

      if mod(x,1) ~= 0
          disp('x is a non-integer value between 3 and 6')
      else
          disp('x is a integer value between 3 and 6')
      end

elseif x < 3
    disp('x is less than 6')
end

The above code checks to see what range x falls in, then enters an if/else statement that determines whether it is evenly divisible by one. If not, this means x is not an integer value and the corresponding text is displayed. Here, you could get rid of the nesting if you liked by using statements like elseif x >=3 && x <= 6 && mod(x,1) ~= 0, but eventually it would get messy and difficult to read.

%grade = [];
grade = 75;

if ~isempty(grade)
    if grade > 70
        disp('Assignment passed!')
    else
        disp('Assignment failed!')
    end
else
    disp('No grade found for this assignment!')
end

Here's another example in which we have to use the nesting in order to check for cases where a blank grade was given.

[Jan]

No, if ~isempty(grade) && grade > 75 does not produce an error for empty grade. It is the purpose of the && operator to short-circuit, here not to evaluate the right part, if the left part is FALSE already.

[Evan]

Oops! I guess I'm remembering incorrectly. I'll remove the incorrect portion of my code. Hmm... I must've been thinking of a scenario where the class of the variable being compared led to an error in the second condition.

[Jan]

Thanks for the correction, Evan.

Answer 2

[Nathan Crosty]

this = 222;
that = 111;

if this == 333
  disp('this')
elseif that == 444
  disp('that')
else 
  this = 555;
  if this == 222
    disp('this')
  else
    disp('that')
  end
end

[Evan]

Because the nested if statement contained within the else segment of the the outer statement has no option for "false" values, this would be more clear to display with an if/elseif statement rather than the nested version. Might be a bit misleading to use it as an example.

Answer 3

[Sohrab Abedini]

The examples were great. However, I could not still find a solution to this problem of mine: I don't know how to write it in matlab code->

if n=4 then -> c=2, d=3 or c=3 , d=2.

I wondering if writing "or" is acceptable in result statement. it seems wrong but I have to do it somehow. --- The actual problem is changing a 2nd rank Tensor to a 4th rank tensor through Voigt mapping. which is quite easy vise versa and so difficult in this way. I might be able to solve it if I understand to write "or" or sth like that in if statement.

Answer 4

[Nava Subedi]

Can someone help me to what is wrong with my code:

function [l, m, n] = sort3([a b c])
  if a>=b && a>=c 
      if b>=c
        l = c;
      elseif b<=c
        l = b;
      else l = a;
      end
   elseif b>=a && b>=c
      if a>=c
        m = c;
      elseif a<=c
        m = a;
      else m = b;
      end
   else c>=a && c>=b
      if a>=b
        n = b;
      elseif a<=b
        n = a;
      else n = c;
      end
  end

I am trying to write nested if statement.

[Stephen23]

This is not MATLAB syntax:

 function [l, m, n] = sort3([a b c])

It looks like you are trying to write Python, or something similar. The correct MATLAB syntax is shown in the online beginners tutorials, the documentation, and lots of online forums:

function [l, m, n] = sort3(a, b, c)

Anyone can read the MATLAB documentation for free. It explains how MATLAB works:

https://www.mathworks.com/help/matlab/getting-started-with-matlab.html

Answer 5

[Jobin Geevarghese Thampi]

what is the wrong with this code?. It is supposed to give 22

[Jobin Geevarghese Thampi]

[Walter Roberson]

You are showing us the file prac.m but matlab is not going to know to look inside prac.m for the function summa() . You are getting some other summa() function.