两种类型的注释

类型的评论

A comment is a line (or multiple lines) of text that are inserted into the source code to explain what the code is doing. In C++ there are two kinds of comments.

注释是一个线（或多线）的文本，插入到源代码解释代码是做什么的。在C++中有两种类型的注释。

The // symbol begins a C++ single-line comment, which tells the compiler to ignore everything to the end of the line. For example:

/ /符号开始一个C++单行注释，它告诉编译器忽略一切到终点。比如说呢。

1	cout << "Hello world!" << endl; // Everything from here to the right is ignored.

Typically, the single line comment is used to make a quick comment about a single line of code.

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cout << "Hello world!" << endl; // cout and endl live in the iostream library cout << "It is very nice to meet you!" << endl; // these comments make the code hard to read cout << "Yeah!" << endl; // especially when lines are different lengths

Having comments to the right of a line can make the both the code and the comment hard to read, particularly if the line is long. Consequently, the // comment is often placed above the line it is commenting.

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// cout and endl live in the iostream library cout << "Hello world!" << endl;    // this is much easier to read cout << "It is very nice to meet you!" << endl;    // don't you think so? cout << "Yeah!" << endl;

The /* and */ pair of symbols denotes a C-style multi-line comment. Everything in between the symbols is ignored.

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/* This is a multi-line comment.    This line will be ignored.    So will this one. */

Since everything between the symbols is ignored, you will sometimes see programmers “beautify” their multiline comments:

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/* This is a multi-line comment.  * the matching asterisks to the left  * can make this easier to read  */

Multi-line style comments do not nest. Consequently, the following will have unexpected results:

1 2	/* This is a multiline /* comment */ this is not inside the comment */ //                                ^ comment ends here

规则：不要嵌套注释里面其他的评论