Proper use of errors

Question

I m using TypeScript for a reasonably large project  and am wondering what the standard is for the use of Errors  For example  say I hand an index out of bounds exception in Java   throw new IndexOutOfBoundsException      Would the equivalent statement in TypeScript be   throw new Error  Index Out of Bounds      What other ways could I accomplish this  What is the accepted standard

User · Answer

The convention for out of range in JavaScript is using RangeError  To check the type use if   else   instanceof starting at the most specific to the most generic try       throw new RangeError      catch  e       if  e instanceof RangeError           console log  out of range          else            throw

User · Answer

Someone posted this link to the MDN in a comment  and I think it was very helpful  It describes things like ErrorTypes very thoroughly      EvalError --- Creates an instance representing an error that occurs regarding the global function eval         InternalError  --- Creates an instance representing an error that occurs when an internal error in the JavaScript engine is thrown  E g     too much recursion        RangeError --- Creates an instance representing an error that occurs when a numeric variable or parameter is outside of its valid   range       ReferenceError --- Creates an instance representing an error that occurs when de-referencing an invalid reference       SyntaxError --- Creates an instance representing a syntax error that occurs while parsing code in eval         TypeError --- Creates an instance representing an error that occurs when a variable or parameter is not of a valid type       URIError --- Creates an instance representing an error that occurs when encodeURI   or decodeURI   are passed invalid parameters

User · Answer

Don t forget about switch statements    Ensure handling with default  instanceof can match on superclass  ES6 constructor will match on the exact class  Easier to read     x000D   x000D  function handleError     x000D      try   x000D          throw new RangeError    x000D        x000D      catch  e    x000D          switch  e constructor    x000D              case Error       return console log  generic    x000D              case RangeError  return console log  range    x000D              default          return console log  unknown    x000D            x000D        x000D    x000D   x000D  handleError    x000D   x000D   x000D

User · Answer

Simple solution to emit and show message by Exception   try     throw new TypeError  Error message      catch  e     console log   lt Error gt e  message    conversion to Error type     Caution  Above is not a solution if we don t know what kind of error can be emitted from the block  In such cases type guards should be used and proper handling for proper error should be done - take a look on  Moriarty answer

[exception] Proper use of errors

Examples related to exception

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