why two = for elseif

Question

Tor Fredrik Hove 2011-10-15

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/18382-why-two-for-elseif

采纳的回答： Walter Roberson

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?

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Answer 1

Walter Roberson 2011-10-15

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https://ww2.mathworks.cn/matlabcentral/answers/18382-why-two-for-elseif#answer_24688

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".

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Jan 2011-10-15

@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 2011-10-15

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.

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