std::getline
Defined in header <string> | | |
|---|---|---|
template< class CharT, class Traits, class Allocator > std::basic_istream<CharT,Traits>& getline( std::basic_istream<CharT,Traits>& input, std::basic_string<CharT,Traits,Allocator>& str, CharT delim ); | (1) | |
template< class CharT, class Traits, class Allocator > std::basic_istream<CharT,Traits>& getline( std::basic_istream<CharT,Traits>&& input, std::basic_string<CharT,Traits,Allocator>& str, CharT delim ); | (1) | (since C++11) |
template< class CharT, class Traits, class Allocator > std::basic_istream<CharT,Traits>& getline( std::basic_istream<CharT,Traits>& input, std::basic_string<CharT,Traits,Allocator>& str ); | (2) | |
template< class CharT, class Traits, class Allocator > std::basic_istream<CharT,Traits>& getline( std::basic_istream<CharT,Traits>&& input, std::basic_string<CharT,Traits,Allocator>& str ); | (2) | (since C++11) |
getline从输入流中读取字符并将它们放入字符串：
1%29表现为UnformattedInputFunction，除了input.gcount()不受影响。在构造和检查Sentry对象之后，执行以下操作：
1%29次电话str.erase()
2%29提取字符input并将它们附加到str直到出现下列情况之一之前，%28已按所列顺序检查为%29
的文件结束条件为%29input在这种情况下，getline集eofbit...
B%29下一个可用的输入字符是delim，经Traits::eq(c, delim)，在这种情况下，分隔符字符是从input，但没有附加到str...
C%29str.max_size()字符已被存储，在这种情况下getline集failbit然后回来。
3%29如果由于任何原因没有提取字符%28---即使是丢弃的分隔符%29---getline集failbit然后回来。
2%29getline(input, str, input.widen('\n'))即，默认分隔符是尾行字符。
参数
input | - | the stream to get data from |
|---|---|---|
str | - | the string to put the data into |
delim | - | the delimiter character |
返回值
input...
注记
在空格分隔输入后立即使用时，例如在int n;std::cin>> n;，，，getline使用留在输入流上的尾行字符。运算符>>马上回来。一个常见的解决方案是忽略输入行中的所有剩余字符。cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');在切换到以线路为导向的输入之前。
例
下面的示例演示如何使用getline函数读取用户%27 s输入和如何逐行处理文件。
二次
#include <string>
#include <iostream>
#include <sstream>
int main()
{
// greet the user
std::string name;
std::cout << "What is your name? ";
std::getline(std::cin, name);
std::cout << "Hello " << name << ", nice to meet you.\n";
// read file line by line
std::istringstream input;
input.str("1\n2\n3\n4\n5\n6\n7\n");
int sum = 0;
for (std::string line; std::getline(input, line); ) {
sum += std::stoi(line);
}
std::cout << "\nThe sum is: " << sum << "\n";
}二次
可能的产出：
二次
What is your name? John Q. Public
Hello John Q. Public, nice to meet you.
The sum is 28二次
另见
getline | extracts characters until the given character is found (public member function of std::basic_istream) |
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