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Difference between revisions of "cpp/string/basic string/substr"

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< cpp‎ | string‎ | basic string
(example: add substr from the end)
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Returns a substring {{tt|[pos, pos+count)}}. If the requested substring lasts past the end of the string, or if {{c|1=count == npos}}, the returned substring is {{tt|[pos, size())}}.  
+
Returns a substring {{tt|[pos, pos+count)}}. If the requested substring extends past the end of the string, or if {{c|1=count == npos}}, the returned substring is {{tt|[pos, size())}}.  
  
 
===Parameters===
 
===Parameters===

Revision as of 12:30, 15 April 2013

 
 
 
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basic_string substr( size_type pos = 0,
                     size_type count = npos );

Returns a substring [pos, pos+count). If the requested substring extends past the end of the string, or if count == npos, the returned substring is [pos, size()).

Contents

Parameters

pos - position of the first character to include
count - length of the substring

Return value

String containing the substring [pos, pos+count).

Exceptions

std::out_of_range if pos > size().

Complexity

Linear in count

Example

#include <string>
#include <iostream>
 
int main()
{
    std::string a = "0123456789abcdefghij";
 
    std::string sub1 = a.substr(10);
    std::cout << sub1 << '\n';
 
    std::string sub2 = a.substr(5, 3);
    std::cout << sub2 << '\n';
 
    std::string sub3 = a.substr(12, 100);
    std::cout << sub3 << '\n';
 
    std::string sub4 = a.substr(a.size()-3, 50);
    std::cout << sub4 << '\n';
}

Output:

abcdefghij
567
cdefghij
hij

See also

Template:cpp/string/basic string/dcl list copy