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Why is null an object and what's the difference between null and undefined?

... variables, however, produces an exception: > unknownVariable ReferenceError: unknownVariable is not defined null: used by programmers to indicate “no value”, e.g. as a parameter to a function. Examining a variable: console.log(typeof unknownVariable === "undefined"); // true var foo; c...
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Make a UIButton programmatically in Swift

...ion that takes no parameter, the colon is not needed and may even cause an error if not removed. – Dave G Sep 2 '15 at 3:29  |  show 5 more co...
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Installing Bower on Ubuntu

...using the command below, but as ours are location in nodejs we will get an error No such file or directory. $ /usr/bin/env node We can manually fix this by creating a symlink. $ sudo ln -s /usr/bin/nodejs /usr/bin/node Now check Node.js is installed correctly by using. $ /usr/bin/env node &gt...
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Controlling number of decimal digits in print output in R

...-15) y1 <- rnorm(50, 1 + 1e-15, 1e-15) t.test(x1, y1) #Should throw an error x2 <- rnorm(50, 0, 1e-15) y2 <- rnorm(50, 1e-15, 1e-15) t.test(x2, y2) #ok In the first case, differences between numbers only occur after many significant figures, so the data are "nearly constant". In the s...
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Load image from resources area of project in C#

... @SriHarshaChilakapati typeof(this); doesn't compile. You get Error 1 Type expected – John Gibb Jan 7 '14 at 16:32  |  show 1 mor...
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Using MVC HtmlHelper extensions from Razor declarative views

... For the benefit of searchers, I got the same error when creating MVC views as part of a class library (for component re-use). The solution, partially alluded to above, was to add the following using statements at the top of the .cshtml file: @using System.Web.Mvc @usin...
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IllegalArgumentException or NullPointerException for a null parameter? [closed]

...hing different as a result? Are you trying to communicate a more specific error message? But you can do that in the exception message text anyway, as you should for all other incorrect parameters. Fourth, all other incorrect parameter data will be IAE, so why not be consistent? Why is it that an...
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Does Python have “private” variables in classes?

...t will fail: >>>x = A() >>>x.__var # this will return error: "A has no attribute __var" >>>x.printVar() # this gives back 123 But you can easily get away with this: >>>x.__dict__ # this will show everything that is contained in object x # w...
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How to customize a Spinner in Android

...height value to "?attr/dropdownListPreferredItemHeight" or you will get an error: "Error: Attribute is not public" – Loenix Jun 14 '16 at 6:05 9 ...
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How to format a float in javascript?

...est for ex. 451.175 it will be ok - 451.18. So it's difficult to spot this error at a first glance. The problem is with multiplying: try 551.175 * 100 = 55117.49999999999 (ups!) So my idea is to treat it with toFixed() before using Math.round(); function roundFix(number, precision) { var mult...