Difference between revisions of "Template:cpp/container/back"
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m (Text replace - "/sidebar" to "/navbar") |
(I'm assuming that calling back on an empty container is UB as well, b/c we'd be dereferencing an invalid iterator) |
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Returns reference to the last element in the container. | Returns reference to the last element in the container. | ||
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| + | Calling {{tt|back}} on an empty container is undefined. | ||
===Parameters=== | ===Parameters=== | ||
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===Complexity=== | ===Complexity=== | ||
Constant | Constant | ||
| + | |||
| + | ===Notes=== | ||
| + | For a container {{tt|c}}, the expression {{c|return c.back();}} is equivalent to {{c|{ auto tmp {{=}} c.end(); --tmp; return *tmp; } }} | ||
===Example=== | ===Example=== | ||
Revision as of 05:40, 26 June 2012
Template:ddcl list begin <tr class="t-dcl ">
<td class="t-dcl-nopad">reference back();
</td>
<td class="t-dcl-nopad"> </td> <td class="t-dcl-nopad"> </td> </tr> <tr class="t-dcl ">
<td class="t-dcl-nopad">const_reference back() const;
</td>
<td class="t-dcl-nopad"> </td> <td class="t-dcl-nopad"> </td> </tr> Template:ddcl list end
Returns reference to the last element in the container.
Calling back on an empty container is undefined.
Contents |
Parameters
(none)
Return value
reference to the last element
Complexity
Constant
Notes
For a container c, the expression return c.back(); is equivalent to { auto tmp = c.end(); --tmp; return *tmp; }
Example
The following code uses back to display the last element of a std::{{{1}}}<char>:
Run this code
#include <{{{1}}}> #include <iostream> int main() { std::{{{1}}}<char> letters {'o', 'm', 'g', 'w', 't', 'f'}; if (!letters.empty()) { std::cout << "The last character is: " << letters.back() << '\n'; } }
Output:
The last character is f
