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In IE and Chrome, typing this into the JavaScript console throws an exception:
{} == false // "SyntaxError: Unexpected token ==" However, all of these statements are evaluated with no problem:
false == {} // false ({} == false) // false var a = {}; a == false // false Is this intentional behavior? Why does this happen?
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Since it returns a boolean value, there would be no need of throwing an exception, simply return false.
The calculate method should check for an exception and if there is no exception, return the calculated value to the main function i.e. v1+v2 or v1-v2; Else if an exception exists then it should print the error statement and the value that is returned from the calculate method to the main method should be 0.0(Not ...
Definition and UsageThe throw statement throws (generates) an error. The technical term for this is: The throw statement throws an exception. The exception can be a JavaScript String, a Number, a Boolean or an Object: throw "Too big"; // throw a text.
throw new Error() Creating objects using ES6 classes requires the use of new and extending Error via a class is the only way to preserve stack traces. throw Error() is like a Javascript string, a number, a boolean, or an object. It returns specific errors as defined in the message value which is passed as an argument.
In the console, when you start a statement with {}, you are not creating an object literal, but a code block (i.e. the same block as you would make with an if statement or a loop body). A symbol like == is then obviously not expected afterwards.
If you think of a code block, you know that something like a = 5; could come after it:
if (some_condition) { // do something } a = 5; You can then use this to test in the console, and find that it works just fine:
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