2024年4月20日发(作者：)
GetLine
目录
getline功能
getline参数
getline说明
编辑本段
getline功能
getline是string类对象的成员函数,属于string IO 操作。用于读
取整行文本
编辑本段
getline参数
getline(cin,str);
cin:输入流
str:string对象
编辑本段
getline说明
getline函数从输入流的下一行读取，并保存读取的内容到str中，但
不包括换行符。getline 函数将 istream 参数作为返回值，和输入操作符
一样也把它用作判断条件。
范例：
#include
#include
using namespace std;
int main()
{
string line;
while(getline(cin,line))
cout< return 0; } 结果： 输入 line1 ----回车换行 显示为空 输入 line2 ----回车换行 显示 line1 输入 line3 ----回车换行 显示 line2 ----（以此类推） getline的原型如下： getline(char* c,int i,char c); 表示读入i个字符，或者遇到结束符c为止的字符数，保存到c 中。 getline(char*,int); 表示读入i个字符到c中。注意读入的字符数应比实际的大1，因为读 入的是字符串，字符串将会以'0'作为结束，如果你要读入3个字符，那么i的值应该为4。 注意getline会读取并丢弃分界符。 后面的自已搞定，创建一个文件流类对象，然后用这个文件流来调用getline函数，比如 ifstream hy1(“”)//创建hy1流，并打开文件以便读取内容。 char c[333]; e(c,3,'0'); //表示，把hy1流关联的hyong1中3个字符或者遇到'0'的字符数读入 到c中。 假设有一个叫 的文件, 它包含以下内容: Fry: One Jillion dollars. [Everyone gasps.] Auctioneer: Sir, that's not a number. 数据读取， 测试 。 以下就是基于 的数据读取操作: #include include #include using namespace std; //输出空行 void OutPutAnEmptyLine() { cout<<"n"; } //读取方式: 逐词读取, 词之间用空格区分 //read data from the file, Word By Word //when used in this manner, we'll get space-delimited bits of text from the file //but all of the whitespace that separated words (including newlines) was lost. void ReadDataFromFileWBW() { ifstream fin(""); string s; while( fin >> s ) { cout << "Read from file: " << s << endl; } } //读取方式: 逐行读取, 将行读入字符数组, 行之间用回车换行区分 //If we were interested in preserving whitespace, //we could read the file in Line-By-Line using the I/O getline() function. void ReadDataFromFileLBLIntoCharArray() { ifstream fin(""); const int LINE_LENGTH = 100; char str[LINE_LENGTH]; while( e(str,LINE_LENGTH) ) { cout << "Read from file: " << str << endl; } } //读取方式: 逐行读取, 将行读入字符串, 行之间用回车换行区分 //If you want to avoid reading into character arrays, //you can use the C++ string getline() function to read lines into strings void ReadDataFromFileLBLIntoString() { ifstream fin(""); string s; while( getline(fin,s) ) { cout << "Read from file: " << s << endl; } } //带错误检测的读取方式 //Simply evaluating an I/O object in a boolean context will return false //if any errors have occurred void ReadDataWithErrChecking() { string filename = ""; ifstream fin( filename.c_str()); if( !fin ) { cout << "Error opening " << filename << " for input" << endl; exit(-1); } } int main() { ReadDataFromFileWBW(); //逐词读入字符串 OutPutAnEmptyLine(); //输出空行 ReadDataFromFileLBLIntoCharArray(); //逐词读入字符数组 OutPutAnEmptyLine(); //输出空行 ReadDataFromFileLBLIntoString(); //逐词读入字符串 OutPutAnEmptyLine(); //输出空行 ReadDataWithErrChecking(); //带检测的读取 return 0; } 输出结果为: Read from file: Fry: Read from file: One Read from file: Jillion Read from file: dollars. Read from file: [Everyone Read from file: gasps.] Read from file: Auctioneer: Read from file: Sir, Read from file: that's Read from file: not Read from file: a Read from file: number. Read from file: 数据读取， Read from file: 测试 Read from file: 。 Read from file: Fry: One Jillion dollars. Read from file: [Everyone gasps.] Read from file: Auctioneer: Sir, that's not a number. Read from file: 数据读取， 测试 。 Read from file: Fry: One Jillion dollars. Read from file: [Everyone gasps.] Read from file: Auctioneer: Sir, that's not a number. Read from file: 数据读取， 测试 。 Error opening for input Press any key to continue 来自
发布评论