Here I twice to define variables of type int * Q, dev - C an error, says not to be redefined, [/color]



[color=# 000080] shown below in the teaching video program, two of type int * p variables, not an error, is this why? Is to define variables for many times, I think the writing below should be an error, but did not report errors...


I think I should rewrite into like this, so don't complain, good-looking, also please brother, explain, I appreciate the younger brother taught me is too slow, die electricity, several electricity, SCM... What will you do later...

CodePudding user response:

Because he was inside the {}, involving a hidden variables, local variables to redefine will hide at the beginning of the variable, you two variables the same area, can't hide, so an error

CodePudding user response:

This is a question of a scope
Different scopes the same symbols to express different entities are permitted

The code inside this sentence to you
Error is within a scope defines the same symbol
No error is the same symbols appear in different scopes

CodePudding user response:

Lz should look for the book entry level learning the knowledge of the scope of the scope of the variable

CodePudding user response:

Compound statements are wrapped up the scope of the block scope
Two p defined in different block scope it is legal

CodePudding user response:

Because p is in a code block, the scope is visible inside a code block; And Q is the scope of the main function can be seen, so is to redefine,

P in the for loop is visible in the circulation and use of no problem, the code block (cycle) is not met,