Rationale for declaring variables at the top of each block in C? [closed]

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I am teaching C programming and I am quite strict regarding variable declaration. As we use the C11 standard and knowing that the students would later use other programming language, I teach this rule:

Any declared symbol should have its scope as narrow as possible.

(a better phrasing would be appreciated)

In other words, a variable should be declared as late as possible to reduce its visibility from others.

This rule has several advantages:

• It often increases readability
• It forces the programmer to not reuse symbols for other purposes (global tmp variable)
• It eases any refactoring by minimizing the diff on a fix
• It is then easier to switch to other languages

My question is: is there any strong rationale other than preserving the compatibility with C89 for declaring all variables at the top of a function block?

I would say that 70% of the books / exercises / examples found on the internet still use this C89 habit so some students always question this rule.

来源：https://stackoverflow.com/questions/65749619/rationale-for-declaring-variables-at-the-top-of-each-block-in-c