boolean

Don’t understand static boolean behavior

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static in this context means “local” (to the translation unit). There will be multiple copies of read_mess in your program, one per translation unit which is not the same thing as a header file. (In your case you can most likely approximate “translation unit” as .cpp or .c or .cc file). Probably what you meant to do was to declare an extern variable, or static class … Read more

How to convert string to boolean php

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Strings always evaluate to boolean true unless they have a value that’s considered “empty” by PHP (taken from the documentation for empty): “” (an empty string); “0” (0 as a string) If you need to set a boolean based on the text value of a string, then you’ll need to check for the presence or otherwise of that value. … Read more

C++ printing boolean, what is displayed?

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The standard streams have a boolalpha flag that determines what gets displayed — when it’s false, they’ll display as 0 and 1. When it’s true, they’ll display as false and true. There’s also an std::boolalpha manipulator to set the flag, so this: …produces output like: For what it’s worth, the actual word produced when boolalpha is set to true is localized–that is, <locale> has a num_put category that handles numeric conversions, … Read more

How to create a numpy array of all True or all False?

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numpy allows the creation of arrays of all ones or all zeros very easily: e.g. numpy.ones((2, 2)) or numpy.zeros((2, 2)) Since True and False are represented in Python as 1 and 0, respectively, we have only to specify this array should be boolean using the optional dtype parameter and we are done. numpy.ones((2, 2), dtype=bool) … Read more