Split, merge, mix, extract pages and rotate PDF files Commercial PDFsam Enhanced and PDFsam Visual are two commercial solutions for professional users. Some other assumption might be violated, or you might have introduced a bug somewhere that is causing an exception. PDFsam Basic is a free and open source solution for casual users. This makes it very easy to assume that the exception you get is the one you were thinking about when you wrote the catch block.īut it might not be. JavaScript (in a rather glaring omission) doesn’t provide direct support for selectively catching exceptions: either you catch them all or you don’t catch any. But we don’t know what, or which exception it caused. When a catch body is entered, all we know is that something in our try body caused an exception. Such exceptions can be caught just like your own exceptions.
Invalid uses of the language, such as referencing a nonexistent variable, looking up a property on null, or calling something that’s not a function, will also result in exceptions being raised. Pdfsam is an open source tool (GPL license) designed to handle pdf files. An unhandled exception is a reasonable way to signal a broken program, and the JavaScript console will, on modern browsers, provide you with some information about which function calls were on the stack when the problem occurred.įor problems that are expected to happen during routine use, crashing with an unhandled exception is not a very friendly response. In browsers, a description of the error typically gets written to the JavaScript console (reachable through the browser’s Tools or Developer menu).įor programmer mistakes or problems that the program cannot possibly handle, just letting the error go through is often okay. What this means differs between environments. When an exception makes it all the way to the bottom of the stack without being caught, it gets handled by the environment. Ovviamente è una continuazione dal post precendente 😊
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