C++ In a Nutshell

Name

clock function — Gets the processor time

Synopsis

clock_t clock(  )

The clock function returns the amount of processor time used since an implementation-defined start time. The time is returned in implementation-defined units. There are CLOCKS_PER_SEC units per second.

The value returned by the clock function is not useful by itself but is intended to be used by comparing it with the value returned from an earlier call to clock. For example, the first statement in the main function might be a call to clock; the difference between subsequent calls and the original call tell you how much time has elapsed since the program started.

If the environment cannot provide the processor time, static_cast<clock_t>(-1) is returned.

See Also

clock_t type, CLOCKS_PER_SEC macro, time function