Shulou(Shulou.com)06/02 Report--

Today, I will talk to you about how to use the String class in C++, which may not be well understood by many people. In order to make you understand better, the editor has summarized the following content for you. I hope you can get something from this article.

1. The string in C++ is different from the string in C

There is no concept of string in C language, it is actually an array of characters, but there is a header file "string.h" in C, which provides function interfaces such as string concatenation, copy, comparison and so on. String in C++ is a string class, so you need to include the string header file when using it. Since string is a class under the std namespace, you also need to introduce the std namespace. Here is the sample code:

# include

Using std::string

2. Definition and initialization of string object in C++.

The string class in C++ provides several ways to initialize a string object:

String str1; / / default initialization, str1 is an empty string

String str2 (str1); / / initialize with a known string using the copy constructor

String str21 = str1

String str2 = ("Hello World!")

String str3 ("HelloWorld")

3. The operator of C++ string object (take the string s as an example)

Os > s / / write the input stream to s

Getline (is, s) / / read a line from is to s

S.empty () / / determines whether the string s is empty

S.size () / / gets the size of the string s

S1 = = S2 / / compare whether the string S1 equals the string S2

S1 + S2 / / concatenate the strings S1 and S2 into a new amount string

Read input from the command line and save to a string:

# include

Int main ()

{

Std::string line

While (getline (cin, line))

If (line.size () > 1024)

Cout

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