小编cha*_*ola的帖子

可能重复:
在C++书籍中,数组绑定必须是常量表达式,但为什么以下代码有效？

看到这段代码

#include<iostream>
int main
{
using namespace std;
int a=7;
char arr[a];
return 0;
}

在我的书中写道,array_size必须是一个常量但是代码块没有给出错误...

它不是唯一的例子......还有其他一些例子.

谁是错误的IDE,编译器或任何其他的东西???

使用较新或较旧的书会导致这样的问题？

看看这个Javascript代码:

var myString = new String();
myString.myObject = "myObject...";

//works fine as it shows "myObject..."
console.log("myString.myObject        :" + myString.myObject);
//OK myObject is also a string so it should give length and it works fine
console.log("myString.myObject.length :" + myString.myObject.length);
//it should not give anything or undefined since nothing is given to myString
console.log("myString                 :" + myString);
//myString is not yet defined so it should give undefined or 0..
console.log("myString.length          :" + myString.length);

//lets make a simple assignment
myString = myString.myObject;
//it …