Difference between revisions of "cpp/string/basic string/substr"
From cppreference.com
< cpp | string | basic string
(Undo revision 90069 by 24.6.100.196 (talk)) |
(+example where the exception is thrown) |
||
| Line 44: | Line 44: | ||
std::string sub4 = a.substr(a.size()-3, 50); | std::string sub4 = a.substr(a.size()-3, 50); | ||
std::cout << sub4 << '\n'; | std::cout << sub4 << '\n'; | ||
| + | |||
| + | try { | ||
| + | std::string sub5 = a.substr(a.size()+3, 50); | ||
| + | } catch(const std::out_of_range& e) { | ||
| + | std::cout << "pos exceeds string size\n"; | ||
| + | } | ||
} | } | ||
| output= | | output= | ||
| Line 50: | Line 56: | ||
cdefghij | cdefghij | ||
hij | hij | ||
| + | pos exceeds string size | ||
}} | }} | ||
Revision as of 04:32, 4 April 2017
| basic_string substr( size_type pos = 0, size_type count = npos ) const; |
||
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
Run this code
#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'; try { std::string sub5 = a.substr(a.size()+3, 50); } catch(const std::out_of_range& e) { std::cout << "pos exceeds string size\n"; } }
Output:
abcdefghij 567 cdefghij hij pos exceeds string size
See also
| copies characters (public member function) | |
| returns the number of characters (public member function) | |
| finds the first occurrence of the given substring (public member function) |
