Exception handling

When executing a program, abnormal conditions can occur that force the Julia runtime to throw an exception or error, show the exception message and the line where it occurred, and then exit. For example (follow along with the code in Chapter 4\errors.jl):

  • Using the wrong index for an array, for example, arr = [1,2,3]and then asking for arr[0] causes a program to stop with ERROR: BoundsError()
  • Calling sqrt() on a negative value, for example, sqrt(-3) causes ERROR: DomainError: sqrt will only return a complex result if called with a complex argument, try sqrt(complex(x)); the sqrt(complex(-3)) function gives the correct result 0.0 + 1.7320508075688772im
  • A syntax error in Julia code will usually result in LoadError

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