为什么变量不能以数字开头? [英] Why variable can not start with a Number?

问题描述

我正在PHP中工作，我必须按顺序定义变量以保存在Mysql中.在我的情况下，字段名和变量名必须相同.

I am working in PHP, I have to define variables in sequence to save in Mysql. Both field name and variable name must be same in my case.

我可以这样声明一个变量吗

Can I declare a variable like this

$1 OR $2 etc 

如果不是，为什么不是?如果是，为什么是?

If not why not and if yes why yes?

我尝试过:

$id = 0;
$6  = $_REQUEST['6'];
$7  = $_REQUEST['7'];
$8  = $_REQUEST['8'];

$xary = array('6','7','8','9')

$oAppl->save_record("tablename", $id, "id");

这给了我错误.

我还可以在Mysql中创建和使用同名的字段吗?

Also can I create and use fields in Mysql with the same name?

推荐答案

这是PHP的设计方式.您不能使用数字开头变量名.

This is how PHP was designed. You can't start a variable name with a number.

您可以做的是使用下划线:

What you can do is use underscore:

$_6 = $_REQUEST['6'];

因为变量在PHP中以 $ 开头，所以变量可能以数字开头，但这会使大多数人感到困惑，因为没有其他语言允许变量以数字开头(或至少我什么都不知道.

since variables start with $ in PHP, is would be possible to have variables starting with numbers, but that would be a bit confusing to most people since there is no other language that allows variables starting with numbers (or at least I don't know any).

但是让我们想象一下允许以数字开头的变量.

But let's imagine variables starting with numbers are allowed.

您能想象一个同事对您说: 23等于74吗?这有点令人困惑.听到 n23等于74 更有意义.您知道 n23 是一个变量，而不必明确地说出来.

Can you imagine a coworker saying to you: 23 equals 74? That is a bit confusing. Hearing n23 equals 74 makes more sense. You know n23 is a variable without having to explicitly say that.

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