“变量"的定义是什么? [英] What is the definition of a "variable"?

问题描述

标准指出

实体是值，对象，引用，函数，枚举数，类型，类成员，模板，模板专业化，名称空间，参数包装或这个.

An entity is a value, object, reference, function, enumerator, type, class member, template, template specialization, namespace, parameter pack, or this.

这意味着变量" 不是实体.

但在标准中进一步说:

每个表示实体的名称都由声明引入.每个表示标签的名称都由goto引入陈述(6.6.4)或标记陈述(6.1).

Every name that denotes an entity is introduced by a declaration. Every name that denotes a label is introduced either by a goto statement (6.6.4) or a labeled-statement (6.1).

和

通过引用以外的引用的声明来引入变量非静态数据成员或对象.变量名称表示引用或对象.

A variable is introduced by the declaration of a reference other than a non-static data member or of an object. The variable’s name denotes the reference or object.

我从这两个引号中假设变量是一个名称.

I'm assume from this two quotes that a variable is a name.

这是因为变量是由引用声明引入的，每个表示实体的名称都是由声明引入的.但是变量的名称是什么意思?根据定义，变量也是一个名称.

It is because the variable is introduced by declaration of reference and every name that denotes entity introduced by a declaration. But what does a variable's name mean? A variable is also a name by definition.

推荐答案

术语变量的定义在这方面有点含糊，但是通过查看c ++标准中术语变量的各种用法，它看起来像变量是一种特殊的实体.它可以是对象，也可以是引用.但是，并非所有对象或引用都是变量，只有 [basic]/6 中所述的那些对象或引用:

The definition of the term variable is a bit ambiguous in this respect, but by looking at the various uses of the term variable in the c++ standard, it looks like a variable is a special kind of entity. It is either an object or a reference. However, not all objects or references are variables, only the ones introduced the way described in [basic]/6:

通过引用以外的引用的声明来引入变量非静态数据成员或对象.变量的名称(如果有)，表示参考或对象.

A variable is introduced by the declaration of a reference other than a non-static data member or of an object. The variable's name, if any, denotes the reference or object.

请注意，某些变量未命名，例如下面的示例中的函数f的参数:

Note that some variables are unnamed, for example the parameter of the function f in the example below:

void f(int) {}

int main() {}

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