Maybe some possible questions in your Cpp-Primer/ch02

[ghost]

1.exercise 2.5 lose answer of (d)

2.exercise 2.6 your answer is “The first line's integer is decimal, the second line's integer is octal.”, but I think second line’s first integer isn’t octal . 9 doesn’t appear in Octal like that A doesn’t appear in decimal.

3.exercise 2.27 your answer think that “int *const p2 = &i2” is legal,
But if i2 is a variable of double type ,what’s the answer ?so it’s not strict .
So (d),(f) have same questions ,we don’t know i2 what type it is .

1. exercise 2.31 r1 = v2 is illegal. Error message : invalid initialization of reference of type 'int&' from expression of type 'const int'

My English level is very poor , so can you understand what I want to express?thanks!

[pezy]

Hi, @cxs944745612 Good to see you. 😄

1 and 2, you are right, and I have tried to fix it.

3 int *const p2 = &i2, we can judge the variable type according by it's name. Or, the question make no sense. Thus, i2 should be an integer, rather than double as you say.

4 I can't sure whether it will appear this error message. I am try to list the related codes as following:

const int v2 = 0;
int v1 = v2;
int &r1 = v1;
// above is previous exercise (Exercise 2.30)
r1 = v2;

Use Clang 3.5 and gcc 4.9.2, All passed. Could you please tell me what environment do you have?

Thx a lot for bug reporting. 👍

[ghost]

I'm very sorry ,it's my fault .You're right!
what's more,you say"we can judge the variable type according by it's name",it means that we keep i2 as a default integer variable .( i: integer, d: double, f: float. so d2 is a double variable in c++ primer ? like this？)
My English level is very poor , so can you understand what I want to express? I really want to say Chinese ! thanks a lot for your guidance！

[jjjasperd]

我觉着你们俩可以用中文讨论来着：）

[pezy]

@cxs944745612 @jjjasperd

那咱们以后就用中文吧～ 🇨🇳

i: integer, d: double, f: float. so d2 is a double variable in c++ primer ? like this？

是的，就是这样，这本书的命名很讲究，也为初学者培养好不乱命名的好习惯。除了你提到的，第二章里，还有 r 代表 reference, c 代表 const, p 代表 pointer.

[ghost]

好的，非常感谢！我有些新的问题请教您，我又提了两个问题在知乎上邀请您回答了，如果有时间的话，麻烦您了。

[pezy]

@cxs944745612 真的抱歉，周末有些事耽搁了，明天我帮你看看～ 🏇

[ghost]

没事没事，您有时间就看，非常感谢您的无私帮助！