why two = for elseif

Why do one need two = for elseif here: http://bildr.no/view/1001050

I tried with only one and it does not work

Why does one not need two = here:

http://bildr.no/view/1001051

I have made the script work it is just I don't get why one need two = for the menu?

Answer 1

[Walter Roberson]

In MATLAB, a single = is either direct assignment or a representation that assignment will happen (such as in a "for K=1:10" statement.)

In MATLAB, == is always comparison of values.

There are other comparison operators that include a single = as part of the token, such as <= . That must be read as a pair, not as "<" and "=" separately, just like "if" is not the same thing as "i f".

[Tor Fredrik Hove]

in this function grade what is the difference between grade and quiz that makes quiz assigned to two = and grade only one =?

http://bildr.no/view/1001074

[Jan]

@Tor: a=b assigns the value of b to the variable a. a==b compares the values of a and b and replies TRUE, if they are equal, FALSE otherwise.

I strongly recommend to delete your comment, if you do not have the written consent of the author of the book. I assume posting a copy of the book conflicts with the copy right.

[Walter Roberson]

In most countries, posting of a limited section like that would be considered "fair use" or "fair dealings", as it is for the purpose of learning, analysis, and understanding.

The more that the posted section is trimmed down to the least amount required to make the point, the stronger the exemption or defense is.